diff --git a/third_party/variant/.gitignore b/third_party/variant/.gitignore
index a9bc8605e..e656256b6 100644
--- a/third_party/variant/.gitignore
+++ b/third_party/variant/.gitignore
@@ -6,3 +6,4 @@ deps
 *.gcda
 *.gcno
 .ycm_extra_conf.pyc
+mason_packages
diff --git a/third_party/variant/.gitmodules b/third_party/variant/.gitmodules
new file mode 100644
index 000000000..44fba9a2f
--- /dev/null
+++ b/third_party/variant/.gitmodules
@@ -0,0 +1,3 @@
+[submodule ".mason"]
+	path = .mason
+	url = https://github.com/mapbox/mason.git
diff --git a/third_party/variant/.travis.yml b/third_party/variant/.travis.yml
index 99d0b48c2..4119d9ef1 100644
--- a/third_party/variant/.travis.yml
+++ b/third_party/variant/.travis.yml
@@ -1,4 +1,4 @@
-language: c
+language: generic
 
 sudo: false
 
@@ -6,49 +6,50 @@ sudo: false
 addons_shortcuts:
   addons_clang35: &clang35
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.5', 'boost-latest' ]
-      packages: [ 'clang-3.5', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.5' ]
+      packages: [ 'clang-3.5', 'llvm-3.5-dev' ]
   addons_clang36: &clang36
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.6', 'boost-latest' ]
-      packages: [ 'clang-3.6', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.6' ]
+      packages: [ 'clang-3.6' ]
   addons_clang37: &clang37
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.7', 'boost-latest' ]
-      packages: [ 'clang-3.7', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.7' ]
+      packages: [ 'clang-3.7' ]
   addons_clang38: &clang38
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise', 'boost-latest' ]
-      packages: [ 'clang-3.8', 'libboost1.55-all-dev']
+      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.8' ]
+      packages: [ 'clang-3.8']
+  addons_clang39: &clang39
+    apt:
+      sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise' ]
+      packages: [ 'clang-3.9']
   addons_gcc47: &gcc47
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'boost-latest' ]
-      packages: [ 'g++-4.7', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test' ]
+      packages: [ 'g++-4.7' ]
   addons_gcc48: &gcc48
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'boost-latest' ]
-      packages: [ 'g++-4.8', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test' ]
+      packages: [ 'g++-4.8' ]
   addons_gcc49: &gcc49
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'boost-latest' ]
-      packages: [ 'g++-4.9', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test' ]
+      packages: [ 'g++-4.9' ]
   addons_gcc5: &gcc5
     apt:
-      sources: [ 'ubuntu-toolchain-r-test', 'boost-latest' ]
-      packages: [ 'g++-5', 'libboost1.55-all-dev' ]
+      sources: [ 'ubuntu-toolchain-r-test' ]
+      packages: [ 'g++-5' ]
 
 matrix:
   include:
-    - os: osx
-      osx_image: xcode6
-      compiler: clang
     - os: osx
       osx_image: xcode7
       env: TEST_GYP_BUILD=True
       compiler: clang
     - os: linux
       compiler: "clang35"
-      env: CXX=clang++-3.5
+      env: CXX=clang++-3.5 COVERAGE=True
       addons: *clang35
     - os: linux
       compiler: "clang36"
@@ -56,7 +57,7 @@ matrix:
       addons: *clang36
     - os: linux
       compiler: "clang37"
-      env: CXX=clang++-3.7 COVERAGE=True
+      env: CXX=clang++-3.7
       addons: *clang37
     - os: linux
       compiler: "clang38"
@@ -66,6 +67,11 @@ matrix:
       compiler: "clang38"
       env: CXX=clang++-3.8 CXX_STD=c++14
       addons: *clang38
+    # not whitelisted yet: https://github.com/travis-ci/apt-package-whitelist/issues/2764
+    #- os: linux
+    #  compiler: "clang39"
+    #  env: CXX=clang++-3.9
+    #  addons: *clang39
     - os: linux
       compiler: "gcc47"
       env: CXX=g++-4.7
@@ -96,7 +102,6 @@ before_install:
  - if [[ $(uname -s) == 'Linux' ]]; then
      export PYTHONPATH=$(pwd)/.local/lib/python2.7/site-packages;
    else
-     brew install boost;
      export PYTHONPATH=$(pwd)/.local/lib/python/site-packages;
    fi
  - if [[ ${COVERAGE:-0} == 'True' ]]; then
@@ -106,11 +111,7 @@ before_install:
 install:
  - make test
  - make bench
- - if [[ $(uname -s) == 'Linux' ]]; then
-     make sizes /usr/include/boost/variant.hpp;
-   else
-     make sizes `brew --prefix`/include/boost/variant.hpp;
-   fi
+ - make sizes
  - scripts/run_compilation_failure_tests.sh
  - if [[ ${TEST_GYP_BUILD:-0} == 'True' ]]; then
      make clean;
@@ -123,5 +124,5 @@ script:
     make coverage;
     ./out/cov-test;
     cp unit*gc* test/;
-    ./.local/bin/cpp-coveralls -i optional.hpp -i recursive_wrapper.hpp -i variant.hpp -i variant_io.hpp --gcov-options '\-lp';
+    ./.local/bin/cpp-coveralls --gcov /usr/bin/llvm-cov-3.5 --gcov-options '\-lp' -i optional.hpp -i recursive_wrapper.hpp -i variant.hpp -i variant_io.hpp;
    fi
diff --git a/third_party/variant/Jamroot b/third_party/variant/Jamroot
index 1e98cf555..3e863e25a 100644
--- a/third_party/variant/Jamroot
+++ b/third_party/variant/Jamroot
@@ -1,4 +1,4 @@
-# Inofficial and incomplete build file using Boost build system.
+# Unofficial and incomplete build file using Boost build system.
 # You should use make unless you know what you are doing.
 
 local BOOST_DIR = "/usr/local" ;
@@ -17,9 +17,10 @@ exe variant-test
     .//chrono
     :
     <include>$(BOOST_DIR)/include
-    <include>./
+    <include>./include
+    <include>./test/include
     #<define>SINGLE_THREADED
-    <variant>release:<cxxflags>-march=native
+    <variant>release:<cxxflags>"-march=native -Wweak-vtables"
     ;
 
 
@@ -31,7 +32,8 @@ exe binary-visitor-test
     .//chrono
     :
     <include>$(BOOST_DIR)/include
-    <include>./
+    <include>./include
+    <include>./test/include
     <variant>release:<cxxflags>-march=native
     ;
 
@@ -43,7 +45,8 @@ exe recursive-wrapper-test
     .//chrono
     :
     <include>$(BOOST_DIR)/include
-    <include>./
+    <include>./include
+    <include>./test/include
     <variant>release:<cxxflags>-march=native
     ;
 
@@ -55,7 +58,8 @@ exe unique-ptr-test
     .//chrono
     :
     <include>$(BOOST_DIR)/include
-    <include>./
+    <include>./include
+    <include>./test/include
     <variant>release:<cxxflags>-march=native
     ;
 
@@ -68,6 +72,7 @@ exe reference_wrapper_test
     .//chrono
     :
     <include>$(BOOST_DIR)/include
-    <include>./
+    <include>./include
+    <include>./test/include
     <variant>release:<cxxflags>-march=native
     ;
diff --git a/third_party/variant/Makefile b/third_party/variant/Makefile
index 36652511d..10ab7b5f0 100644
--- a/third_party/variant/Makefile
+++ b/third_party/variant/Makefile
@@ -1,32 +1,23 @@
+MASON = .mason/mason
+BOOST_VERSION = boost 1.60.0
 
 CXX := $(CXX)
 CXX_STD ?= c++11
 
-BOOST_LIBS = -lboost_timer -lboost_system -lboost_chrono
+BOOST_FLAGS = `$(MASON) cflags $(BOOST_VERSION)`
 RELEASE_FLAGS = -O3 -DNDEBUG -march=native -DSINGLE_THREADED -fvisibility-inlines-hidden
 DEBUG_FLAGS = -O0 -g -DDEBUG -fno-inline-functions
 COMMON_FLAGS = -Wall -pedantic -Wextra -Wsign-compare -Wsign-conversion -Wshadow -Wunused-parameter -std=$(CXX_STD)
 CXXFLAGS := $(CXXFLAGS)
 LDFLAGS := $(LDFLAGS)
 
-OS:=$(shell uname -s)
-ifeq ($(OS),Darwin)
-	CXXFLAGS += -stdlib=libc++
-	LDFLAGS += -stdlib=libc++ -F/ -framework CoreFoundation
-else
-    BOOST_LIBS += -lrt
-endif
+ALL_HEADERS = $(shell find include/mapbox/ '(' -name '*.hpp' ')')
 
-ifeq (sizes,$(firstword $(MAKECMDGOALS)))
-  RUN_ARGS := $(wordlist 2,$(words $(MAKECMDGOALS)),$(MAKECMDGOALS))
-  $(eval $(RUN_ARGS):;@:)
-  ifndef RUN_ARGS
-  $(error sizes target requires you pass full path to boost variant.hpp)
-  endif
-  .PHONY: $(RUN_ARGS)
-endif
+all: out/bench-variant out/unique_ptr_test out/unique_ptr_test out/recursive_wrapper_test out/binary_visitor_test out/lambda_overload_test out/hashable_test
 
-all: out/bench-variant out/unique_ptr_test out/unique_ptr_test out/recursive_wrapper_test out/binary_visitor_test
+mason_packages:
+	git submodule update --init .mason
+	$(MASON) install $(BOOST_VERSION)
 
 ./deps/gyp:
 	git clone --depth 1 https://chromium.googlesource.com/external/gyp.git ./deps/gyp
@@ -36,25 +27,33 @@ gyp: ./deps/gyp
 	make V=1 -C ./out tests
 	./out/Release/tests
 
-out/bench-variant-debug: Makefile test/bench_variant.cpp variant.hpp recursive_wrapper.hpp
+out/bench-variant-debug: Makefile mason_packages test/bench_variant.cpp
 	mkdir -p ./out
-	$(CXX) -o out/bench-variant-debug test/bench_variant.cpp -I./ -pthreads $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS)
+	$(CXX) -o out/bench-variant-debug test/bench_variant.cpp -I./include -Itest/include -pthreads $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
 
-out/bench-variant: Makefile test/bench_variant.cpp variant.hpp recursive_wrapper.hpp
+out/bench-variant: Makefile mason_packages test/bench_variant.cpp
 	mkdir -p ./out
-	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS)
+	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
 
-out/unique_ptr_test: Makefile test/unique_ptr_test.cpp variant.hpp recursive_wrapper.hpp
+out/unique_ptr_test: Makefile mason_packages test/unique_ptr_test.cpp
 	mkdir -p ./out
-	$(CXX) -o out/unique_ptr_test test/unique_ptr_test.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS)
+	$(CXX) -o out/unique_ptr_test test/unique_ptr_test.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
 
-out/recursive_wrapper_test: Makefile test/recursive_wrapper_test.cpp variant.hpp recursive_wrapper.hpp
+out/recursive_wrapper_test: Makefile mason_packages test/recursive_wrapper_test.cpp
 	mkdir -p ./out
-	$(CXX) -o out/recursive_wrapper_test test/recursive_wrapper_test.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS)
+	$(CXX) -o out/recursive_wrapper_test test/recursive_wrapper_test.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
 
-out/binary_visitor_test: Makefile test/binary_visitor_test.cpp variant.hpp variant_io.hpp recursive_wrapper.hpp
+out/binary_visitor_test: Makefile mason_packages test/binary_visitor_test.cpp
 	mkdir -p ./out
-	$(CXX) -o out/binary_visitor_test test/binary_visitor_test.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS)
+	$(CXX) -o out/binary_visitor_test test/binary_visitor_test.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
+
+out/lambda_overload_test: Makefile mason_packages test/lambda_overload_test.cpp
+	mkdir -p ./out
+	$(CXX) -o out/lambda_overload_test test/lambda_overload_test.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
+
+out/hashable_test: Makefile mason_packages test/hashable_test.cpp
+	mkdir -p ./out
+	$(CXX) -o out/hashable_test test/hashable_test.cpp -I./include -Itest/include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS)
 
 bench: out/bench-variant out/unique_ptr_test out/unique_ptr_test out/recursive_wrapper_test out/binary_visitor_test
 	./out/bench-variant 100000
@@ -66,11 +65,11 @@ out/unit.o: Makefile test/unit.cpp
 	mkdir -p ./out
 	$(CXX) -c -o $@ test/unit.cpp -Itest/include $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS)
 
-out/%.o: test/t/%.cpp Makefile optional.hpp recursive_wrapper.hpp variant.hpp variant_io.hpp
+out/%.o: test/t/%.cpp Makefile $(ALL_HEADERS)
 	mkdir -p ./out
-	$(CXX) -c -o $@ $< -I. -Itest/include $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS)
+	$(CXX) -c -o $@ $< -Iinclude -Itest/include $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS)
 
-out/unit: out/unit.o out/binary_visitor_1.o out/binary_visitor_2.o out/binary_visitor_3.o out/binary_visitor_4.o out/binary_visitor_5.o out/binary_visitor_6.o out/issue21.o out/mutating_visitor.o out/optional.o out/recursive_wrapper.o out/sizeof.o out/unary_visitor.o out/variant.o
+out/unit: out/unit.o out/binary_visitor_1.o out/binary_visitor_2.o out/binary_visitor_3.o out/binary_visitor_4.o out/binary_visitor_5.o out/binary_visitor_6.o out/issue21.o out/issue122.o out/mutating_visitor.o out/optional.o out/recursive_wrapper.o out/sizeof.o out/unary_visitor.o out/variant.o
 	mkdir -p ./out
 	$(CXX) -o $@ $^ $(LDFLAGS)
 
@@ -79,14 +78,14 @@ test: out/unit
 
 coverage:
 	mkdir -p ./out
-	$(CXX) -o out/cov-test --coverage test/unit.cpp test/t/*.cpp -I./ -Itest/include $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS)
+	$(CXX) -o out/cov-test --coverage test/unit.cpp test/t/*.cpp -I./include -Itest/include $(DEBUG_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS)
 
-sizes: Makefile variant.hpp recursive_wrapper.hpp
+sizes: Makefile
 	mkdir -p ./out
-	@$(CXX) -o ./out/our_variant_hello_world.out variant.hpp $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/our_variant_hello_world.out
-	@$(CXX) -o ./out/boost_variant_hello_world.out $(RUN_ARGS) $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/boost_variant_hello_world.out
-	@$(CXX) -o ./out/our_variant_hello_world ./test/our_variant_hello_world.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/our_variant_hello_world
-	@$(CXX) -o ./out/boost_variant_hello_world ./test/boost_variant_hello_world.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/boost_variant_hello_world
+	@$(CXX) -o ./out/our_variant_hello_world.out include/mapbox/variant.hpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/our_variant_hello_world.out
+	@$(CXX) -o ./out/boost_variant_hello_world.out `$(MASON) prefix boost 1.60.0`/include/boost/variant.hpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(BOOST_FLAGS) &&  du -h ./out/boost_variant_hello_world.out
+	@$(CXX) -o ./out/our_variant_hello_world ./test/our_variant_hello_world.cpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) &&  du -h ./out/our_variant_hello_world
+	@$(CXX) -o ./out/boost_variant_hello_world ./test/boost_variant_hello_world.cpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS)  $(BOOST_FLAGS) &&  du -h ./out/boost_variant_hello_world
 
 profile: out/bench-variant-debug
 	mkdir -p profiling/
@@ -102,9 +101,9 @@ clean:
 	rm -f test/*gcov
 	rm -f *.gcda *.gcno
 
-pgo: out Makefile variant.hpp recursive_wrapper.hpp
-	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS) -pg -fprofile-generate
+pgo: out Makefile
+	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS) -pg -fprofile-generate
 	./test-variant 500000 >/dev/null 2>/dev/null
-	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./ $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_LIBS) -fprofile-use
+	$(CXX) -o out/bench-variant test/bench_variant.cpp -I./include $(RELEASE_FLAGS) $(COMMON_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(BOOST_FLAGS) -fprofile-use
 
 .PHONY: sizes test
diff --git a/third_party/variant/README.md b/third_party/variant/README.md
index 24cdb570b..0e274b03b 100644
--- a/third_party/variant/README.md
+++ b/third_party/variant/README.md
@@ -1,11 +1,169 @@
 # Mapbox Variant
 
-An alternative to `boost::variant` for C++11.
+An header-only alternative to `boost::variant` for C++11 and C++14
 
 [![Build Status](https://secure.travis-ci.org/mapbox/variant.svg)](https://travis-ci.org/mapbox/variant)
 [![Build status](https://ci.appveyor.com/api/projects/status/v9tatx21j1k0fcgy)](https://ci.appveyor.com/project/Mapbox/variant)
 [![Coverage Status](https://coveralls.io/repos/mapbox/variant/badge.svg?branch=master&service=github)](https://coveralls.io/r/mapbox/variant?branch=master)
 
+## Introduction
+
+Variant's basic building blocks are:
+- `variant<Ts...>` - a type-safe representation for sum-types / discriminated unions
+- `recursive_wrapper<T>` - a helper type to represent recursive "tree-like" variants
+- `apply_visitor(visitor, myVariant)` - to invoke a custom visitor on the variant's underlying type
+- `get<T>()` - a function to directly unwrap a variant's underlying type
+- `.match([](Type){})` - a variant convenience member function taking an arbitrary number of lambdas creating a visitor behind the scenes and applying it to the variant
+
+
+### Basic Usage - HTTP API Example
+
+Suppose you want to represent a HTTP API response which is either a JSON result or an error:
+
+```c++
+struct Result {
+  Json object;
+};
+
+struct Error {
+  int32_t code;
+  string message;
+};
+```
+
+You can represent this at type level using a variant which is either an `Error` or a `Result`:
+
+```c++
+using Response = variant<Error, Result>;
+
+Response makeRequest() {
+  return Error{501, "Not Implemented"};
+}
+
+Response ret = makeRequest();
+```
+
+To see which type the `Response` holds you pattern match on the variant unwrapping the underlying value:
+
+```c++
+ret.match([] (Result r) { print(r.object); }
+          [] (Error e)  { print(e.message); });
+```
+
+Instead of using the variant's convenience `.match` pattern matching function you can create a type visitor functor and use `apply_visitor` manually:
+
+```c++
+struct ResponseVisitor {
+  void operator()(Result r) const {
+    print(r.object);
+  }
+
+  void operator()(Error e) const {
+    print(e.message);
+  }
+};
+
+ResponseVisitor visitor;
+apply_visitor(visitor, ret);
+```
+
+In both cases the compiler makes sure you handle all types the variant can represent at compile.
+
+
+### Recursive Variants - JSON Example
+
+[JSON](http://www.json.org/) consists of types `String`, `Number`, `True`, `False`, `Null`, `Array` and `Object`.
+
+
+```c++
+struct String { string value; };
+struct Number { double value; };
+struct True   { };
+struct False  { };
+struct Null   { };
+struct Array  { vector<?> values; };
+struct Object { unordered_map<string, ?> values; };
+```
+
+This works for primitive types but how do we represent recursive types such as `Array` which can hold multiple elements and `Array` itself, too?
+
+For these use cases Variant provides a `recursive_wrapper` helper type which lets you express recursive Variants.
+
+```c++
+struct String { string value; };
+struct Number { double value; };
+struct True   { };
+struct False  { };
+struct Null   { };
+
+// Forward declarations only
+struct Array;
+struct Object;
+
+using Value = variant<String, Number, True, False, Null, recursive_wrapper<Array>, recursive_wrapper<Object>>;
+
+struct Array {
+  vector<Value> values;
+};
+
+struct Object {
+  unordered_map<string, Value> values;
+};
+```
+
+For walkig the JSON representation you can again either create a `JSONVisitor`:
+
+```c++
+struct JSONVisitor {
+
+  void operator()(Null) const {
+    print("null");
+  }
+
+  // same for all other JSON types
+};
+
+JSONVisitor visitor;
+apply_visitor(visitor, json);
+```
+
+Or use the convenience `.match` pattern matching function:
+
+```c++
+json.match([] (Null) { print("null"); },
+           ...);
+```
+
+To summarize: use `recursive_wrapper` to represent recursive "tree-like" representations:
+
+```c++
+struct Empty { };
+struct Node;
+
+using Tree = variant<Empty, recursive_wrapper<Node>>;
+
+struct Node {
+  uint64_t value;
+}
+```
+### Advanced Usage Tips
+
+Creating type aliases for variants is a great way to reduce repetition.
+Keep in mind those type aliases are not checked at type level, though.
+We recommend creating a new type for all but basic variant usage:
+
+```c++
+// the compiler can't tell the following two apart
+using APIResult = variant<Error, Result>;
+using FilesystemResult = variant<Error, Result>;
+
+// new type
+struct APIResult : variant<Error, Result> {
+  using Base = variant<Error, Result>;
+  using Base::Base;
+}
+```
+
 
 ## Why use Mapbox Variant?
 
@@ -45,6 +203,9 @@ implementations](doc/other_implementations.md).
 Want to know more about the upcoming standard? Have a look at our
 [overview](doc/standards_effort.md).
 
+Most modern high-level languages provide ways to express sum types directly.
+If you're curious have a look at Haskell's pattern matching or Rust's and Swift's enums.
+
 
 ## Depends
 
@@ -55,19 +216,14 @@ Tested with:
  - g++-4.7
  - g++-4.8
  - g++-4.9
- - g++-5
+ - g++-5.2
  - clang++-3.5
  - clang++-3.6
  - clang++-3.7
  - clang++-3.8
+ - clang++-3.9
  - Visual Studio 2015
 
-## Usage
-
-There is nothing to build, just include `variant.hpp` and
-`recursive_wrapper.hpp` in your project. Include `variant_io.hpp` if you need
-the `operator<<` overload for variant.
-
 
 ## Unit Tests
 
@@ -93,15 +249,6 @@ On Windows run `scripts/build-local.bat`.
 
 ## Benchmarks
 
-The benchmarks depend on:
-
- - Boost headers (for benchmarking against `boost::variant`)
- - Boost built with `--with-timer` (used for benchmark timing)
-
-On Unix systems set your boost includes and libs locations and run `make test`:
-
-    export LDFLAGS='-L/opt/boost/lib'
-    export CXXFLAGS='-I/opt/boost/include'
     make bench
 
 
diff --git a/third_party/variant/optional.hpp b/third_party/variant/include/mapbox/optional.hpp
similarity index 97%
rename from third_party/variant/optional.hpp
rename to third_party/variant/include/mapbox/optional.hpp
index 1185894e7..d84705c1a 100644
--- a/third_party/variant/optional.hpp
+++ b/third_party/variant/include/mapbox/optional.hpp
@@ -6,7 +6,7 @@
 #include <type_traits>
 #include <utility>
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 namespace mapbox {
 namespace util {
@@ -22,7 +22,7 @@ class optional
 
     variant<none_type, T> variant_;
 
-  public:
+public:
     optional() = default;
 
     optional(optional const& rhs)
diff --git a/third_party/variant/recursive_wrapper.hpp b/third_party/variant/include/mapbox/recursive_wrapper.hpp
similarity index 96%
rename from third_party/variant/recursive_wrapper.hpp
rename to third_party/variant/include/mapbox/recursive_wrapper.hpp
index 4becdd689..4ffcbd7c9 100644
--- a/third_party/variant/recursive_wrapper.hpp
+++ b/third_party/variant/include/mapbox/recursive_wrapper.hpp
@@ -29,7 +29,7 @@ class recursive_wrapper
         this->get() = rhs;
     }
 
-  public:
+public:
     using type = T;
 
     /**
@@ -42,9 +42,9 @@ class recursive_wrapper
      * @throws any exception thrown by the default constructur of T.
      */
     recursive_wrapper()
-        : p_(new T){};
+        : p_(new T){}
 
-    ~recursive_wrapper() noexcept { delete p_; };
+    ~recursive_wrapper() noexcept { delete p_; }
 
     recursive_wrapper(recursive_wrapper const& operand)
         : p_(new T(operand.get())) {}
diff --git a/third_party/variant/variant.hpp b/third_party/variant/include/mapbox/variant.hpp
similarity index 71%
rename from third_party/variant/variant.hpp
rename to third_party/variant/include/mapbox/variant.hpp
index db5d3c86b..fb0f77e6d 100644
--- a/third_party/variant/variant.hpp
+++ b/third_party/variant/include/mapbox/variant.hpp
@@ -10,8 +10,10 @@
 #include <type_traits>
 #include <typeinfo>
 #include <utility>
+#include <functional>
 
-#include "recursive_wrapper.hpp"
+#include <mapbox/recursive_wrapper.hpp>
+#include <mapbox/variant_visitor.hpp>
 
 // clang-format off
 // [[deprecated]] is only available in C++14, use this for the time being
@@ -29,21 +31,26 @@
 
 
 #ifdef _MSC_VER
- // https://msdn.microsoft.com/en-us/library/bw1hbe6y.aspx
- #ifdef NDEBUG
-  #define VARIANT_INLINE __forceinline
- #else
-  #define VARIANT_INLINE __declspec(noinline)
- #endif
+// https://msdn.microsoft.com/en-us/library/bw1hbe6y.aspx
+# ifdef NDEBUG
+#  define VARIANT_INLINE __forceinline
+# else
+#  define VARIANT_INLINE //__declspec(noinline)
+# endif
 #else
- #ifdef NDEBUG
-  #define VARIANT_INLINE inline __attribute__((always_inline))
- #else
-  #define VARIANT_INLINE __attribute__((noinline))
- #endif
+# ifdef NDEBUG
+#  define VARIANT_INLINE //inline __attribute__((always_inline))
+# else
+#  define VARIANT_INLINE __attribute__((noinline))
+# endif
 #endif
 // clang-format on
 
+// Exceptions
+#if defined( __EXCEPTIONS) || defined( _MSC_VER)
+#define HAS_EXCEPTIONS
+#endif
+
 #define VARIANT_MAJOR_VERSION 1
 #define VARIANT_MINOR_VERSION 1
 #define VARIANT_PATCH_VERSION 0
@@ -58,7 +65,7 @@ namespace util {
 class bad_variant_access : public std::runtime_error
 {
 
-  public:
+public:
     explicit bad_variant_access(const std::string& what_arg)
         : runtime_error(what_arg) {}
 
@@ -72,7 +79,7 @@ struct MAPBOX_VARIANT_DEPRECATED static_visitor
 {
     using result_type = R;
 
-  protected:
+protected:
     static_visitor() {}
     ~static_visitor() {}
 };
@@ -88,8 +95,8 @@ template <typename T, typename First, typename... Types>
 struct direct_type<T, First, Types...>
 {
     static constexpr std::size_t index = std::is_same<T, First>::value
-                                             ? sizeof...(Types)
-                                             : direct_type<T, Types...>::index;
+        ? sizeof...(Types)
+        : direct_type<T, Types...>::index;
 };
 
 template <typename T>
@@ -98,6 +105,26 @@ struct direct_type<T>
     static constexpr std::size_t index = invalid_value;
 };
 
+#if __cpp_lib_logical_traits >= 201510L
+
+using std::disjunction;
+
+#else
+
+template <typename...>
+struct disjunction : std::false_type {};
+
+template <typename B1>
+struct disjunction<B1> : B1 {};
+
+template <typename B1, typename B2>
+struct disjunction<B1, B2> : std::conditional<B1::value, B1, B2>::type {};
+
+template <typename B1, typename... Bs>
+struct disjunction<B1, Bs...> : std::conditional<B1::value, B1, disjunction<Bs...>>::type {};
+
+#endif
+
 template <typename T, typename... Types>
 struct convertible_type;
 
@@ -105,8 +132,8 @@ template <typename T, typename First, typename... Types>
 struct convertible_type<T, First, Types...>
 {
     static constexpr std::size_t index = std::is_convertible<T, First>::value
-                                             ? sizeof...(Types)
-                                             : convertible_type<T, Types...>::index;
+        ? disjunction<std::is_convertible<T, Types>...>::value ? invalid_value : sizeof...(Types)
+        : convertible_type<T, Types...>::index;
 };
 
 template <typename T>
@@ -118,7 +145,7 @@ struct convertible_type<T>
 template <typename T, typename... Types>
 struct value_traits
 {
-    using value_type = typename std::remove_reference<T>::type;
+    using value_type = typename std::remove_const<typename std::remove_reference<T>::type>::type;
     static constexpr std::size_t direct_index = direct_type<value_type, Types...>::index;
     static constexpr bool is_direct = direct_index != invalid_value;
     static constexpr std::size_t index = is_direct ? direct_index : convertible_type<value_type, Types...>::index;
@@ -127,35 +154,6 @@ struct value_traits
     using target_type = typename std::tuple_element<tindex, std::tuple<void, Types...>>::type;
 };
 
-// check if T is in Types...
-template <typename T, typename... Types>
-struct has_type;
-
-template <typename T, typename First, typename... Types>
-struct has_type<T, First, Types...>
-{
-    static constexpr bool value = std::is_same<T, First>::value || has_type<T, Types...>::value;
-};
-
-template <typename T>
-struct has_type<T> : std::false_type
-{
-};
-
-template <typename T, typename... Types>
-struct is_valid_type;
-
-template <typename T, typename First, typename... Types>
-struct is_valid_type<T, First, Types...>
-{
-    static constexpr bool value = std::is_convertible<T, First>::value || is_valid_type<T, Types...>::value;
-};
-
-template <typename T>
-struct is_valid_type<T> : std::false_type
-{
-};
-
 template <typename T, typename R = void>
 struct enable_if_type
 {
@@ -299,7 +297,7 @@ struct dispatcher<F, V, R, T, Types...>
     {
         if (v.template is<T>())
         {
-            return f(unwrapper<T>::apply_const(v.template get<T>()));
+            return f(unwrapper<T>::apply_const(v.template get_unchecked<T>()));
         }
         else
         {
@@ -311,7 +309,7 @@ struct dispatcher<F, V, R, T, Types...>
     {
         if (v.template is<T>())
         {
-            return f(unwrapper<T>::apply(v.template get<T>()));
+            return f(unwrapper<T>::apply(v.template get_unchecked<T>()));
         }
         else
         {
@@ -325,12 +323,12 @@ struct dispatcher<F, V, R, T>
 {
     VARIANT_INLINE static R apply_const(V const& v, F&& f)
     {
-        return f(unwrapper<T>::apply_const(v.template get<T>()));
+        return f(unwrapper<T>::apply_const(v.template get_unchecked<T>()));
     }
 
     VARIANT_INLINE static R apply(V& v, F&& f)
     {
-        return f(unwrapper<T>::apply(v.template get<T>()));
+        return f(unwrapper<T>::apply(v.template get_unchecked<T>()));
     }
 };
 
@@ -344,8 +342,8 @@ struct binary_dispatcher_rhs<F, V, R, T0, T1, Types...>
     {
         if (rhs.template is<T1>()) // call binary functor
         {
-            return f(unwrapper<T0>::apply_const(lhs.template get<T0>()),
-                     unwrapper<T1>::apply_const(rhs.template get<T1>()));
+            return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()),
+                     unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>()));
         }
         else
         {
@@ -357,8 +355,8 @@ struct binary_dispatcher_rhs<F, V, R, T0, T1, Types...>
     {
         if (rhs.template is<T1>()) // call binary functor
         {
-            return f(unwrapper<T0>::apply(lhs.template get<T0>()),
-                     unwrapper<T1>::apply(rhs.template get<T1>()));
+            return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()),
+                     unwrapper<T1>::apply(rhs.template get_unchecked<T1>()));
         }
         else
         {
@@ -372,14 +370,14 @@ struct binary_dispatcher_rhs<F, V, R, T0, T1>
 {
     VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
     {
-        return f(unwrapper<T0>::apply_const(lhs.template get<T0>()),
-                 unwrapper<T1>::apply_const(rhs.template get<T1>()));
+        return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()),
+                 unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>()));
     }
 
     VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
     {
-        return f(unwrapper<T0>::apply(lhs.template get<T0>()),
-                 unwrapper<T1>::apply(rhs.template get<T1>()));
+        return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()),
+                 unwrapper<T1>::apply(rhs.template get_unchecked<T1>()));
     }
 };
 
@@ -393,8 +391,8 @@ struct binary_dispatcher_lhs<F, V, R, T0, T1, Types...>
     {
         if (lhs.template is<T1>()) // call binary functor
         {
-            return f(unwrapper<T1>::apply_const(lhs.template get<T1>()),
-                     unwrapper<T0>::apply_const(rhs.template get<T0>()));
+            return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()),
+                     unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>()));
         }
         else
         {
@@ -406,8 +404,8 @@ struct binary_dispatcher_lhs<F, V, R, T0, T1, Types...>
     {
         if (lhs.template is<T1>()) // call binary functor
         {
-            return f(unwrapper<T1>::apply(lhs.template get<T1>()),
-                     unwrapper<T0>::apply(rhs.template get<T0>()));
+            return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()),
+                     unwrapper<T0>::apply(rhs.template get_unchecked<T0>()));
         }
         else
         {
@@ -421,14 +419,14 @@ struct binary_dispatcher_lhs<F, V, R, T0, T1>
 {
     VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
     {
-        return f(unwrapper<T1>::apply_const(lhs.template get<T1>()),
-                 unwrapper<T0>::apply_const(rhs.template get<T0>()));
+        return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()),
+                 unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>()));
     }
 
     VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
     {
-        return f(unwrapper<T1>::apply(lhs.template get<T1>()),
-                 unwrapper<T0>::apply(rhs.template get<T0>()));
+        return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()),
+                 unwrapper<T0>::apply(rhs.template get_unchecked<T0>()));
     }
 };
 
@@ -444,8 +442,8 @@ struct binary_dispatcher<F, V, R, T, Types...>
         {
             if (v1.template is<T>())
             {
-                return f(unwrapper<T>::apply_const(v0.template get<T>()),
-                         unwrapper<T>::apply_const(v1.template get<T>())); // call binary functor
+                return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()),
+                         unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor
             }
             else
             {
@@ -465,8 +463,8 @@ struct binary_dispatcher<F, V, R, T, Types...>
         {
             if (v1.template is<T>())
             {
-                return f(unwrapper<T>::apply(v0.template get<T>()),
-                         unwrapper<T>::apply(v1.template get<T>())); // call binary functor
+                return f(unwrapper<T>::apply(v0.template get_unchecked<T>()),
+                         unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor
             }
             else
             {
@@ -486,14 +484,14 @@ struct binary_dispatcher<F, V, R, T>
 {
     VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f)
     {
-        return f(unwrapper<T>::apply_const(v0.template get<T>()),
-                 unwrapper<T>::apply_const(v1.template get<T>())); // call binary functor
+        return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()),
+                 unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor
     }
 
     VARIANT_INLINE static R apply(V& v0, V& v1, F&& f)
     {
-        return f(unwrapper<T>::apply(v0.template get<T>()),
-                 unwrapper<T>::apply(v1.template get<T>())); // call binary functor
+        return f(unwrapper<T>::apply(v0.template get_unchecked<T>()),
+                 unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor
     }
 };
 
@@ -519,7 +517,7 @@ struct less_comp
 template <typename Variant, typename Comp>
 class comparer
 {
-  public:
+public:
     explicit comparer(Variant const& lhs) noexcept
         : lhs_(lhs) {}
     comparer& operator=(comparer const&) = delete;
@@ -527,26 +525,22 @@ class comparer
     template <typename T>
     bool operator()(T const& rhs_content) const
     {
-        T const& lhs_content = lhs_.template get<T>();
+        T const& lhs_content = lhs_.template get_unchecked<T>();
         return Comp()(lhs_content, rhs_content);
     }
 
-  private:
+private:
     Variant const& lhs_;
 };
 
-// True if Predicate matches for all of the types Ts
-template <template <typename> class Predicate, typename... Ts>
-struct static_all_of : std::is_same<std::tuple<std::true_type, typename Predicate<Ts>::type...>,
-                                    std::tuple<typename Predicate<Ts>::type..., std::true_type>>
-{
-};
-
-// True if Predicate matches for none of the types Ts
-template <template <typename> class Predicate, typename... Ts>
-struct static_none_of : std::is_same<std::tuple<std::false_type, typename Predicate<Ts>::type...>,
-                                     std::tuple<typename Predicate<Ts>::type..., std::false_type>>
+// hashing visitor
+struct hasher
 {
+    template <typename T>
+    std::size_t operator()(const T& hashable) const
+    {
+        return std::hash<T>{}(hashable);
+    }
 };
 
 } // namespace detail
@@ -559,20 +553,23 @@ template <typename... Types>
 class variant
 {
     static_assert(sizeof...(Types) > 0, "Template parameter type list of variant can not be empty");
-    static_assert(detail::static_none_of<std::is_reference, Types...>::value, "Variant can not hold reference types. Maybe use std::reference?");
+    static_assert(!detail::disjunction<std::is_reference<Types>...>::value, "Variant can not hold reference types. Maybe use std::reference_wrapper?");
 
-  private:
+private:
     static const std::size_t data_size = detail::static_max<sizeof(Types)...>::value;
     static const std::size_t data_align = detail::static_max<alignof(Types)...>::value;
-
-    using first_type = typename std::tuple_element<0, std::tuple<Types...>>::type;
+public:
+    struct adapted_variant_tag;
+    using types = std::tuple<Types...>;
+private:
+    using first_type = typename std::tuple_element<0, types>::type;
     using data_type = typename std::aligned_storage<data_size, data_align>::type;
     using helper_type = detail::variant_helper<Types...>;
 
     std::size_t type_index;
     data_type data;
 
-  public:
+public:
     VARIANT_INLINE variant() noexcept(std::is_nothrow_default_constructible<first_type>::value)
         : type_index(sizeof...(Types)-1)
     {
@@ -585,7 +582,7 @@ class variant
 
     // http://isocpp.org/blog/2012/11/universal-references-in-c11-scott-meyers
     template <typename T, typename Traits = detail::value_traits<T, Types...>,
-              typename Enable = typename std::enable_if<Traits::is_valid>::type>
+              typename Enable = typename std::enable_if<Traits::is_valid && !std::is_same<variant<Types...>, typename Traits::value_type>::value>::type >
     VARIANT_INLINE variant(T&& val) noexcept(std::is_nothrow_constructible<typename Traits::target_type, T&&>::value)
         : type_index(Traits::index)
     {
@@ -598,13 +595,13 @@ class variant
         helper_type::copy(old.type_index, &old.data, &data);
     }
 
-    VARIANT_INLINE variant(variant<Types...>&& old) noexcept(std::is_nothrow_move_constructible<std::tuple<Types...>>::value)
+    VARIANT_INLINE variant(variant<Types...>&& old) noexcept(std::is_nothrow_move_constructible<types>::value)
         : type_index(old.type_index)
     {
         helper_type::move(old.type_index, &old.data, &data);
     }
 
-  private:
+private:
     VARIANT_INLINE void copy_assign(variant<Types...> const& rhs)
     {
         helper_type::destroy(type_index, &data);
@@ -621,7 +618,7 @@ class variant
         type_index = rhs.type_index;
     }
 
-  public:
+public:
     VARIANT_INLINE variant<Types...>& operator=(variant<Types...>&& other)
     {
         move_assign(std::move(other));
@@ -653,13 +650,20 @@ class variant
         return *this;
     }
 
-    template <typename T>
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE bool is() const
     {
-        static_assert(detail::has_type<T, Types...>::value, "invalid type in T in `is<T>()` for this variant");
         return type_index == detail::direct_type<T, Types...>::index;
     }
 
+    template <typename T,typename std::enable_if<
+                         (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE bool is() const
+    {
+        return type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index;
+    }
+
     VARIANT_INLINE bool valid() const
     {
         return type_index != detail::invalid_value;
@@ -674,9 +678,18 @@ class variant
         type_index = detail::direct_type<T, Types...>::index;
     }
 
+    // get_unchecked<T>()
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T& get_unchecked()
+    {
+        return *reinterpret_cast<T*>(&data);
+    }
+
+#ifdef HAS_EXCEPTIONS
     // get<T>()
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T& get()
     {
         if (type_index == detail::direct_type<T, Types...>::index)
@@ -688,9 +701,18 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T const& get_unchecked() const
+    {
+        return *reinterpret_cast<T const*>(&data);
+    }
+
+#ifdef HAS_EXCEPTIONS
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T const& get() const
     {
         if (type_index == detail::direct_type<T, Types...>::index)
@@ -702,10 +724,20 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
+    // get_unchecked<T>() - T stored as recursive_wrapper<T>
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T& get_unchecked()
+    {
+        return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get();
+    }
+
+#ifdef HAS_EXCEPTIONS
     // get<T>() - T stored as recursive_wrapper<T>
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T& get()
     {
         if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index)
@@ -717,9 +749,18 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T const& get_unchecked() const
+    {
+        return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get();
+    }
+
+#ifdef HAS_EXCEPTIONS
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T const& get() const
     {
         if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index)
@@ -731,10 +772,20 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
+    // get_unchecked<T>() - T stored as std::reference_wrapper<T>
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T& get_unchecked()
+    {
+        return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get();
+    }
+
+#ifdef HAS_EXCEPTIONS
     // get<T>() - T stored as std::reference_wrapper<T>
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T& get()
     {
         if (type_index == detail::direct_type<std::reference_wrapper<T>, Types...>::index)
@@ -746,9 +797,18 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
     template <typename T, typename std::enable_if<
-                              (detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+                          (detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE T const& get_unchecked() const
+    {
+        return (*reinterpret_cast<std::reference_wrapper<T const> const*>(&data)).get();
+    }
+
+#ifdef HAS_EXCEPTIONS
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr>
     VARIANT_INLINE T const& get() const
     {
         if (type_index == detail::direct_type<std::reference_wrapper<T const>, Types...>::index)
@@ -760,6 +820,7 @@ class variant
             throw bad_variant_access("in get<T>()");
         }
     }
+#endif
 
     // This function is deprecated because it returns an internal index field.
     // Use which() instead.
@@ -773,6 +834,13 @@ class variant
         return static_cast<int>(sizeof...(Types)-type_index - 1);
     }
 
+    template <typename T, typename std::enable_if<
+                          (detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+    VARIANT_INLINE static constexpr int which() noexcept
+    {
+        return static_cast<int>(sizeof...(Types)-detail::direct_type<T, Types...>::index - 1);
+    }
+
     // visitor
     // unary
     template <typename F, typename V, typename R = typename detail::result_of_unary_visit<F, first_type>::type>
@@ -805,6 +873,22 @@ class variant
         return detail::binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f));
     }
 
+    // match
+    // unary
+    template <typename... Fs>
+    auto VARIANT_INLINE match(Fs&&... fs) const
+        -> decltype(variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...)))
+    {
+        return variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...));
+    }
+    // non-const
+    template <typename... Fs>
+    auto VARIANT_INLINE match(Fs&&... fs)
+        -> decltype(variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...)))
+    {
+        return variant::visit(*this, ::mapbox::util::make_visitor(std::forward<Fs>(fs)...));
+    }
+
     ~variant() noexcept // no-throw destructor
     {
         helper_type::destroy(type_index, &data);
@@ -884,18 +968,46 @@ auto VARIANT_INLINE apply_visitor(F&& f, V& v0, V& v1) -> decltype(V::binary_vis
 }
 
 // getter interface
+
+#ifdef HAS_EXCEPTIONS
 template <typename ResultType, typename T>
-ResultType& get(T& var)
+auto get(T& var)->decltype(var.template get<ResultType>())
 {
     return var.template get<ResultType>();
 }
+#endif
 
 template <typename ResultType, typename T>
-ResultType const& get(T const& var)
+ResultType& get_unchecked(T& var)
+{
+    return var.template get_unchecked<ResultType>();
+}
+
+#ifdef HAS_EXCEPTIONS
+template <typename ResultType, typename T>
+auto get(T const& var)->decltype(var.template get<ResultType>())
 {
     return var.template get<ResultType>();
 }
+#endif
+
+template <typename ResultType, typename T>
+ResultType const& get_unchecked(T const& var)
+{
+    return var.template get_unchecked<ResultType>();
+}
 } // namespace util
 } // namespace mapbox
 
+// hashable iff underlying types are hashable
+namespace std {
+template <typename... Types>
+struct hash< ::mapbox::util::variant<Types...>> {
+    std::size_t operator()(const ::mapbox::util::variant<Types...>& v) const noexcept
+    {
+        return ::mapbox::util::apply_visitor(::mapbox::util::detail::hasher{}, v);
+    }
+};
+}
+
 #endif // MAPBOX_UTIL_VARIANT_HPP
diff --git a/third_party/variant/variant_io.hpp b/third_party/variant/include/mapbox/variant_io.hpp
similarity index 94%
rename from third_party/variant/variant_io.hpp
rename to third_party/variant/include/mapbox/variant_io.hpp
index e64cbadfc..1456cc5ab 100644
--- a/third_party/variant/variant_io.hpp
+++ b/third_party/variant/include/mapbox/variant_io.hpp
@@ -3,7 +3,7 @@
 
 #include <iosfwd>
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 namespace mapbox {
 namespace util {
@@ -13,7 +13,7 @@ namespace detail {
 template <typename Out>
 class printer
 {
-  public:
+public:
     explicit printer(Out& out)
         : out_(out) {}
     printer& operator=(printer const&) = delete;
@@ -25,7 +25,7 @@ class printer
         out_ << operand;
     }
 
-  private:
+private:
     Out& out_;
 };
 }
diff --git a/third_party/variant/include/mapbox/variant_visitor.hpp b/third_party/variant/include/mapbox/variant_visitor.hpp
new file mode 100644
index 000000000..481eb6520
--- /dev/null
+++ b/third_party/variant/include/mapbox/variant_visitor.hpp
@@ -0,0 +1,38 @@
+#ifndef MAPBOX_UTIL_VARIANT_VISITOR_HPP
+#define MAPBOX_UTIL_VARIANT_VISITOR_HPP
+
+namespace mapbox {
+namespace util {
+
+template <typename... Fns>
+struct visitor;
+
+template <typename Fn>
+struct visitor<Fn> : Fn
+{
+    using type = Fn;
+    using Fn::operator();
+
+    visitor(Fn fn) : Fn(fn) {}
+};
+
+template <typename Fn, typename... Fns>
+struct visitor<Fn, Fns...> : Fn, visitor<Fns...>
+{
+    using type = visitor;
+    using Fn::operator();
+    using visitor<Fns...>::operator();
+
+    visitor(Fn fn, Fns... fns) : Fn(fn), visitor<Fns...>(fns...) {}
+};
+
+template <typename... Fns>
+visitor<Fns...> make_visitor(Fns... fns)
+{
+    return visitor<Fns...>(fns...);
+}
+
+} // namespace util
+} // namespace mapbox
+
+#endif // MAPBOX_UTIL_VARIANT_VISITOR_HPP
diff --git a/third_party/variant/scripts/run_compilation_failure_tests.sh b/third_party/variant/scripts/run_compilation_failure_tests.sh
index c2608fee5..5a1406187 100755
--- a/third_party/variant/scripts/run_compilation_failure_tests.sh
+++ b/third_party/variant/scripts/run_compilation_failure_tests.sh
@@ -14,7 +14,7 @@ fi
 
 error_msg() {
     if [ ! -z "$1" ]; then
-        printf 'output was:\n=======\n%s\n=======\n' "$1"
+	printf 'output was:\n=======\n%s\n=======\n' "$1"
     fi
 }
 
@@ -22,29 +22,28 @@ exit_code=0
 for test_code in $DIR/*.cpp; do
     name=`basename $test_code .cpp`
 
-    result=`${CXX} -std=c++11 -c -o /dev/null -I. ${CXXFLAGS} ${test_code} 2>&1`
+    result=`${CXX} -std=c++11 -c -o /dev/null -I./include ${CXXFLAGS} ${test_code} 2>&1`
     status=$?
 
     if [ $status = 1 ]; then
-        expected=`sed -n -e '/@EXPECTED/s/.*: \+//p' ${test_code}`
-        if echo $result | grep -q "$expected"; then
-            echo "$name [OK]"
-        else
-            echo "$name [FAILED - wrong error message]"
-            echo "Expected error message: $expected"
-            error_msg "$result"
-            exit_code=1
-        fi
+	expected=`sed -n -e '/@EXPECTED/s/.*: \+//p' ${test_code}`
+	if echo $result | grep -q "$expected"; then
+	    echo "$name [OK]"
+	else
+	    echo "$name [FAILED - wrong error message]"
+	    echo "Expected error message: $expected"
+	    error_msg "$result"
+	    exit_code=1
+	fi
     elif [ $status = 0 ]; then
-        echo "$name [FAILED - compile was successful]"
-        error_msg "$result"
-        exit_code=1
+	echo "$name [FAILED - compile was successful]"
+	error_msg "$result"
+	exit_code=1
     else
-        echo "$name [FAILED - unknown error in compile]"
-        error_msg "$result"
-        exit_code=1
+	echo "$name [FAILED - unknown error in compile]"
+	error_msg "$result"
+	exit_code=1
     fi
 done
 
 exit ${exit_code}
-
diff --git a/third_party/variant/test/bench_variant.cpp b/third_party/variant/test/bench_variant.cpp
index 700dac735..567bfe499 100644
--- a/third_party/variant/test/bench_variant.cpp
+++ b/third_party/variant/test/bench_variant.cpp
@@ -1,4 +1,3 @@
-
 #include <algorithm>
 #include <cstdlib>
 #include <iostream>
@@ -8,10 +7,10 @@
 #include <utility>
 #include <vector>
 
-#include <boost/timer/timer.hpp>
-#include <boost/variant.hpp>
+#include "auto_cpu_timer.hpp"
 
-#include "variant.hpp"
+#include <boost/variant.hpp>
+#include <mapbox/variant.hpp>
 
 #define TEXT_SHORT "Test"
 #define TEXT_LONG "Testing various variant implementations with a longish string ........................................."
@@ -140,12 +139,12 @@ int main(int argc, char** argv)
 
         {
             std::cerr << "custom variant: ";
-            boost::timer::auto_cpu_timer t;
+            auto_cpu_timer t;
             run_variant_test(NUM_RUNS);
         }
         {
             std::cerr << "boost variant: ";
-            boost::timer::auto_cpu_timer t;
+            auto_cpu_timer t;
             run_boost_test(NUM_RUNS);
         }
     }
@@ -158,7 +157,7 @@ int main(int argc, char** argv)
             typedef thread_group::value_type value_type;
             thread_group tg;
             std::cerr << "custom variant: ";
-            boost::timer::auto_cpu_timer timer;
+            auto_cpu_timer timer;
             for (std::size_t i = 0; i < THREADS; ++i)
             {
                 tg.emplace_back(new std::thread(run_variant_test, NUM_RUNS));
@@ -171,7 +170,7 @@ int main(int argc, char** argv)
             typedef thread_group::value_type value_type;
             thread_group tg;
             std::cerr << "boost variant: ";
-            boost::timer::auto_cpu_timer timer;
+            auto_cpu_timer timer;
             for (std::size_t i = 0; i < THREADS; ++i)
             {
                 tg.emplace_back(new std::thread(run_boost_test, NUM_RUNS));
diff --git a/third_party/variant/test/binary_visitor_test.cpp b/third_party/variant/test/binary_visitor_test.cpp
index fa0f2ead8..8a7359267 100644
--- a/third_party/variant/test/binary_visitor_test.cpp
+++ b/third_party/variant/test/binary_visitor_test.cpp
@@ -9,8 +9,8 @@
 #include <utility>
 #include <vector>
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 using namespace mapbox;
 
diff --git a/third_party/variant/test/compilation_failure/default_constructor.cpp b/third_party/variant/test/compilation_failure/default_constructor.cpp
index c75a8c16a..b4e83d42b 100644
--- a/third_party/variant/test/compilation_failure/default_constructor.cpp
+++ b/third_party/variant/test/compilation_failure/default_constructor.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED: First type in variant must be default constructible to allow default construction of variant
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 // Checks that the first type in a variant must be default constructible to
 // make the variant default constructible.
diff --git a/third_party/variant/test/compilation_failure/empty_typelist.cpp b/third_party/variant/test/compilation_failure/empty_typelist.cpp
index 69a631c7b..9b8a12571 100644
--- a/third_party/variant/test/compilation_failure/empty_typelist.cpp
+++ b/third_party/variant/test/compilation_failure/empty_typelist.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED: Template parameter type list of variant can not be empty
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 // Empty type list should not work.
 
diff --git a/third_party/variant/test/compilation_failure/equality.cpp b/third_party/variant/test/compilation_failure/equality.cpp
index b99a3086e..36a199006 100644
--- a/third_party/variant/test/compilation_failure/equality.cpp
+++ b/third_party/variant/test/compilation_failure/equality.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED:
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 int main()
 {
diff --git a/third_party/variant/test/compilation_failure/get_type.cpp b/third_party/variant/test/compilation_failure/get_type.cpp
index 5123eb10d..490338926 100644
--- a/third_party/variant/test/compilation_failure/get_type.cpp
+++ b/third_party/variant/test/compilation_failure/get_type.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED: enable_if
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 int main()
 {
diff --git a/third_party/variant/test/compilation_failure/is_type.cpp b/third_party/variant/test/compilation_failure/is_type.cpp
index a79638e8d..95ccff47e 100644
--- a/third_party/variant/test/compilation_failure/is_type.cpp
+++ b/third_party/variant/test/compilation_failure/is_type.cpp
@@ -1,7 +1,6 @@
+// @EXPECTED:
 
-// @EXPECTED: invalid type in T in `is<T>()` for this variant
-
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 int main()
 {
diff --git a/third_party/variant/test/compilation_failure/mutating_visitor_on_const.cpp b/third_party/variant/test/compilation_failure/mutating_visitor_on_const.cpp
index ee77b5614..1706cbff5 100644
--- a/third_party/variant/test/compilation_failure/mutating_visitor_on_const.cpp
+++ b/third_party/variant/test/compilation_failure/mutating_visitor_on_const.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED: const int
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 struct mutating_visitor
 {
diff --git a/third_party/variant/test/compilation_failure/no-reference.cpp b/third_party/variant/test/compilation_failure/no-reference.cpp
index 17123ce8b..2f547fc1f 100644
--- a/third_party/variant/test/compilation_failure/no-reference.cpp
+++ b/third_party/variant/test/compilation_failure/no-reference.cpp
@@ -1,7 +1,6 @@
-
 // @EXPECTED: Variant can not hold reference types
 
-#include <variant.hpp>
+#include <mapbox/variant.hpp>
 
 int main()
 {
diff --git a/third_party/variant/test/hashable_test.cpp b/third_party/variant/test/hashable_test.cpp
new file mode 100644
index 000000000..f3393a9ed
--- /dev/null
+++ b/third_party/variant/test/hashable_test.cpp
@@ -0,0 +1,158 @@
+#include <cstddef>
+#include <cstdlib>
+#include <functional>
+#include <iostream>
+#include <string>
+#include <unordered_set>
+#include <utility>
+
+#include <mapbox/variant.hpp>
+
+using namespace mapbox::util;
+
+void test_singleton()
+{
+    using V = variant<int>;
+
+    V singleton = 5;
+
+    if (std::hash<V>{}(singleton) != std::hash<int>{}(5))
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+}
+
+void test_default_hashable()
+{
+    using V = variant<int, double, std::string>;
+
+    V var;
+
+    // Check int hashes
+    var = 1;
+
+    if (std::hash<V>{}(var) != std::hash<int>{}(1))
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+
+    // Check double hashes
+    var = 23.4;
+
+    if (std::hash<V>{}(var) != std::hash<double>{}(23.4))
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+
+    // Check string hashes
+    var = std::string{"Hello, World!"};
+
+    if (std::hash<V>{}(var) != std::hash<std::string>{}("Hello, World!"))
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+}
+
+struct Hashable
+{
+    static const constexpr auto const_hash = 5;
+};
+
+namespace std {
+template <>
+struct hash<Hashable>
+{
+    std::size_t operator()(const Hashable&) const noexcept
+    {
+        return Hashable::const_hash;
+    }
+};
+}
+
+void test_custom_hasher()
+{
+    using V = variant<int, Hashable, double>;
+
+    V var;
+
+    var = Hashable{};
+
+    if (std::hash<V>{}(var) != Hashable::const_hash)
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+}
+
+void test_hashable_in_container()
+{
+    using V = variant<int, std::string, double>;
+
+    // won't compile if V is not Hashable
+    std::unordered_set<V> vs;
+
+    vs.insert(1);
+    vs.insert(2.3);
+    vs.insert("4");
+}
+
+struct Empty
+{
+};
+
+struct Node;
+
+using Tree = variant<Empty, recursive_wrapper<Node>>;
+
+struct Node
+{
+    Node(Tree left_, Tree right_) : left(std::move(left_)), right(std::move(right_)) {}
+
+    Tree left = Empty{};
+    Tree right = Empty{};
+};
+
+namespace std {
+template <>
+struct hash<Empty>
+{
+    std::size_t operator()(const Empty&) const noexcept
+    {
+        return 3;
+    }
+};
+
+template <>
+struct hash<Node>
+{
+    std::size_t operator()(const Node& n) const noexcept
+    {
+        return 5 + std::hash<Tree>{}(n.left) + std::hash<Tree>{}(n.right);
+    }
+};
+}
+
+void test_recursive_hashable()
+{
+
+    Tree tree = Node{Node{Empty{}, Empty{}}, Empty{}};
+
+    if (std::hash<Tree>{}(tree) != ((5 + (5 + (3 + 3))) + 3))
+    {
+        std::cerr << "Expected variant hash to be the same as hash of its value\n";
+        std::exit(EXIT_FAILURE);
+    }
+}
+
+int main()
+{
+    test_singleton();
+    test_default_hashable();
+    test_custom_hasher();
+    test_hashable_in_container();
+    test_recursive_hashable();
+}
diff --git a/third_party/variant/test/include/auto_cpu_timer.hpp b/third_party/variant/test/include/auto_cpu_timer.hpp
new file mode 100644
index 000000000..b41935fb1
--- /dev/null
+++ b/third_party/variant/test/include/auto_cpu_timer.hpp
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <chrono>
+#include <iostream>
+
+struct auto_cpu_timer {
+    std::chrono::time_point<std::chrono::high_resolution_clock> start;
+    auto_cpu_timer() : start(std::chrono::high_resolution_clock::now()) {
+    }
+    ~auto_cpu_timer() {
+        auto end = std::chrono::high_resolution_clock::now();
+        std::chrono::microseconds elapsed =
+            std::chrono::duration_cast<std::chrono::microseconds>(end - start);
+        std::cerr << elapsed.count() << "us" << std::endl;
+    }
+};
diff --git a/third_party/variant/test/lambda_overload_test.cpp b/third_party/variant/test/lambda_overload_test.cpp
new file mode 100644
index 000000000..9e76d991b
--- /dev/null
+++ b/third_party/variant/test/lambda_overload_test.cpp
@@ -0,0 +1,127 @@
+#include <iostream>
+#include <vector>
+
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_visitor.hpp>
+
+#if __cplusplus >= 201402L
+#define HAS_CPP14_SUPPORT
+#endif
+
+using namespace mapbox::util;
+
+template <typename Left, typename Right>
+using Either = mapbox::util::variant<Left, Right>;
+
+struct Response
+{
+};
+
+struct Error
+{
+};
+
+void test_lambda_overloads()
+{
+    Either<Error, Response> rv;
+
+    rv = Response{};
+
+    auto visitor = make_visitor([](Response) { std::cout << "Response\n"; }, //
+                                [](Error) { std::cout << "Error\n"; });      //
+    apply_visitor(visitor, rv);
+}
+
+void test_lambda_overloads_capture()
+{
+    Either<Error, Response> rv;
+
+    rv = Error{};
+
+    int ok = 0;
+    int err = 0;
+
+    auto visitor = make_visitor([&](Response) { ok += 1; }, //
+                                [&](Error) { err += 1; });  //
+    apply_visitor(visitor, rv);
+
+    std::cout << "Got " << ok << " ok, " << err << " err" << std::endl;
+}
+
+void test_singleton_variant()
+{
+
+    variant<int> singleton;
+    apply_visitor(make_visitor([](int) {}), singleton);
+}
+
+void test_lambda_overloads_sfinae()
+#ifdef HAS_CPP14_SUPPORT
+{
+    variant<int, float, std::vector<int>> var;
+
+    auto visitor = make_visitor([](auto range) -> decltype(std::begin(range), void()) {
+                                    for (auto each : range)
+                                        std::cout << each << ' '; },
+                                [](auto x) -> decltype(std::cout << x, void()) {
+                                    std::cout << x << std::endl;
+                                });
+
+    var = 1;
+    apply_visitor(visitor, var);
+
+    var = 2.f;
+    apply_visitor(visitor, var);
+
+    var = std::vector<int>{4, 5, 6};
+    apply_visitor(visitor, var);
+}
+#else
+{
+}
+#endif
+
+void test_match_singleton()
+{
+    variant<int> singleton = 5;
+    singleton.match([](int) {});
+}
+
+void test_match_overloads()
+{
+    Either<Error, Response> rv;
+
+    rv = Response{};
+
+    rv.match([](Response) { std::cout << "Response\n"; }, //
+             [](Error) { std::cout << "Error\n"; });      //
+}
+
+void test_match_overloads_capture()
+{
+    Either<Error, Response> rv;
+
+    rv = Error{};
+
+    int ok = 0;
+    int err = 0;
+
+    rv.match([&](Response) { ok += 1; }, //
+             [&](Error) { err += 1; });  //
+
+    std::cout << "Got " << ok << " ok, " << err << " err" << std::endl;
+}
+
+int main()
+{
+    test_lambda_overloads();
+    test_singleton_variant();
+    test_lambda_overloads_capture();
+    test_lambda_overloads_sfinae();
+
+    test_match_singleton();
+    test_match_overloads();
+    test_match_overloads_capture();
+}
+
+#undef HAS_CPP14_SUPPORT
diff --git a/third_party/variant/test/our_variant_hello_world.cpp b/third_party/variant/test/our_variant_hello_world.cpp
index be5996b59..07aeb6241 100644
--- a/third_party/variant/test/our_variant_hello_world.cpp
+++ b/third_party/variant/test/our_variant_hello_world.cpp
@@ -1,4 +1,4 @@
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #include <stdexcept>
 
diff --git a/third_party/variant/test/recursive_wrapper_test.cpp b/third_party/variant/test/recursive_wrapper_test.cpp
index 0492af4c8..57143cbf9 100644
--- a/third_party/variant/test/recursive_wrapper_test.cpp
+++ b/third_party/variant/test/recursive_wrapper_test.cpp
@@ -5,9 +5,9 @@
 #include <typeinfo>
 #include <utility>
 
-#include <boost/timer/timer.hpp>
+#include "auto_cpu_timer.hpp"
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 using namespace mapbox;
 
@@ -111,7 +111,7 @@ int main(int argc, char** argv)
 
     int total = 0;
     {
-        boost::timer::auto_cpu_timer t;
+        auto_cpu_timer t;
         for (std::size_t i = 0; i < NUM_ITER; ++i)
         {
             total += util::apply_visitor(test::calculator(), result);
diff --git a/third_party/variant/test/reference_wrapper_test.cpp b/third_party/variant/test/reference_wrapper_test.cpp
index dc1209fe6..3b2085a7a 100644
--- a/third_party/variant/test/reference_wrapper_test.cpp
+++ b/third_party/variant/test/reference_wrapper_test.cpp
@@ -6,7 +6,7 @@
 #include <utility>
 #include <vector>
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 using namespace mapbox;
 
@@ -41,9 +41,12 @@ struct print
     void operator()(line_string const& line) const
     {
         std::cerr << "Line(";
+        bool first = true;
         for (auto const& pt : line)
         {
-            std::cerr << pt.x << " " << pt.y << ",";
+            if (!first) std::cerr << ",";
+            std::cerr << pt.x << " " << pt.y;
+            if (first) first = false;
         }
         std::cerr << ")" << std::endl;
     }
diff --git a/third_party/variant/test/t/binary_visitor_1.cpp b/third_party/variant/test/t/binary_visitor_1.cpp
index 298a40bc0..357922675 100644
--- a/third_party/variant/test/t/binary_visitor_1.cpp
+++ b/third_party/variant/test/t/binary_visitor_1.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " i-d"
 using variant_type = mapbox::util::variant<int, double>;
diff --git a/third_party/variant/test/t/binary_visitor_2.cpp b/third_party/variant/test/t/binary_visitor_2.cpp
index 33768b601..9863ac5a8 100644
--- a/third_party/variant/test/t/binary_visitor_2.cpp
+++ b/third_party/variant/test/t/binary_visitor_2.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " b-i-d"
 using variant_type = mapbox::util::variant<bool, int, double>;
diff --git a/third_party/variant/test/t/binary_visitor_3.cpp b/third_party/variant/test/t/binary_visitor_3.cpp
index d35af4e33..a1c367eb0 100644
--- a/third_party/variant/test/t/binary_visitor_3.cpp
+++ b/third_party/variant/test/t/binary_visitor_3.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " i-d-b"
 using variant_type = mapbox::util::variant<int, double, bool>;
diff --git a/third_party/variant/test/t/binary_visitor_4.cpp b/third_party/variant/test/t/binary_visitor_4.cpp
index daacc1bb8..8cc66ab59 100644
--- a/third_party/variant/test/t/binary_visitor_4.cpp
+++ b/third_party/variant/test/t/binary_visitor_4.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " b-i-d-c"
 using variant_type = mapbox::util::variant<bool, int, double, char>;
diff --git a/third_party/variant/test/t/binary_visitor_5.cpp b/third_party/variant/test/t/binary_visitor_5.cpp
index 28669be07..f6673c887 100644
--- a/third_party/variant/test/t/binary_visitor_5.cpp
+++ b/third_party/variant/test/t/binary_visitor_5.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " b-i-c-d-i"
 using variant_type = mapbox::util::variant<bool, int, char, double, int>;
diff --git a/third_party/variant/test/t/binary_visitor_6.cpp b/third_party/variant/test/t/binary_visitor_6.cpp
index c881b0f36..d259d7396 100644
--- a/third_party/variant/test/t/binary_visitor_6.cpp
+++ b/third_party/variant/test/t/binary_visitor_6.cpp
@@ -1,5 +1,5 @@
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 #define NAME_EXT " b-i-i-d-c-u"
 using variant_type = mapbox::util::variant<bool, int, int, double, char, short int>;
diff --git a/third_party/variant/test/t/binary_visitor_impl.hpp b/third_party/variant/test/t/binary_visitor_impl.hpp
index 4d9a43fe8..f2db68b75 100644
--- a/third_party/variant/test/t/binary_visitor_impl.hpp
+++ b/third_party/variant/test/t/binary_visitor_impl.hpp
@@ -3,7 +3,7 @@
 
 #include "catch.hpp"
 
-#include "variant_io.hpp"
+#include <mapbox/variant_io.hpp>
 
 struct add_visitor
 {
diff --git a/third_party/variant/test/t/issue122.cpp b/third_party/variant/test/t/issue122.cpp
new file mode 100644
index 000000000..12de7d54e
--- /dev/null
+++ b/third_party/variant/test/t/issue122.cpp
@@ -0,0 +1,20 @@
+#include "catch.hpp"
+
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
+
+// https://github.com/mapbox/variant/issues/122
+
+struct X
+{
+    template <typename ValueType>
+    X(const ValueType&)  {}
+};
+
+
+TEST_CASE("Correctly choose appropriate constructor", "[variant]")
+{
+    mapbox::util::variant<X, int> a{123};
+    decltype(a) b(a);
+    REQUIRE(a.which() == b.which());
+}
diff --git a/third_party/variant/test/t/issue21.cpp b/third_party/variant/test/t/issue21.cpp
index b95231396..a33d35982 100644
--- a/third_party/variant/test/t/issue21.cpp
+++ b/third_party/variant/test/t/issue21.cpp
@@ -1,8 +1,7 @@
-
 #include "catch.hpp"
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 // https://github.com/mapbox/variant/issues/21
 
@@ -11,6 +10,12 @@ static int count;
 struct t1
 {
     int value;
+
+    t1(t1 const& rhs)
+        : value(rhs.value)
+    {
+        ++count;
+    }
     t1(int v) : value(v)
     {
         ++count;
@@ -37,7 +42,8 @@ TEST_CASE("set() works cleanly even if the constructor throws ", "[variant]")
 
     count = 0;
     {
-        variant_type v{42};
+        t1 obj{42};
+        variant_type v = obj;
         REQUIRE(v.is<t1>());
         REQUIRE(v.get<t1>().value == 42);
         REQUIRE_THROWS({
diff --git a/third_party/variant/test/t/mutating_visitor.cpp b/third_party/variant/test/t/mutating_visitor.cpp
index f07afb82a..cd4f162eb 100644
--- a/third_party/variant/test/t/mutating_visitor.cpp
+++ b/third_party/variant/test/t/mutating_visitor.cpp
@@ -1,8 +1,8 @@
 
 #include "catch.hpp"
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 #include <string>
 
diff --git a/third_party/variant/test/t/optional.cpp b/third_party/variant/test/t/optional.cpp
index b77bedaa4..8f08f7cd9 100644
--- a/third_party/variant/test/t/optional.cpp
+++ b/third_party/variant/test/t/optional.cpp
@@ -1,7 +1,7 @@
 
 #include "catch.hpp"
 
-#include "optional.hpp"
+#include <mapbox/optional.hpp>
 
 struct dummy
 {
diff --git a/third_party/variant/test/t/recursive_wrapper.cpp b/third_party/variant/test/t/recursive_wrapper.cpp
index b2dec455f..c3d53f0f8 100644
--- a/third_party/variant/test/t/recursive_wrapper.cpp
+++ b/third_party/variant/test/t/recursive_wrapper.cpp
@@ -1,7 +1,7 @@
 
 #include "catch.hpp"
 
-#include "recursive_wrapper.hpp"
+#include <mapbox/recursive_wrapper.hpp>
 
 #include <type_traits>
 #include <utility>
diff --git a/third_party/variant/test/t/sizeof.cpp b/third_party/variant/test/t/sizeof.cpp
index 0e74ce58e..607fabc6d 100644
--- a/third_party/variant/test/t/sizeof.cpp
+++ b/third_party/variant/test/t/sizeof.cpp
@@ -5,8 +5,8 @@
 
 #include "catch.hpp"
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 struct some_struct
 {
diff --git a/third_party/variant/test/t/unary_visitor.cpp b/third_party/variant/test/t/unary_visitor.cpp
index 8df61104f..e447bfa42 100644
--- a/third_party/variant/test/t/unary_visitor.cpp
+++ b/third_party/variant/test/t/unary_visitor.cpp
@@ -1,8 +1,8 @@
 
 #include "catch.hpp"
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 #include <string>
 
diff --git a/third_party/variant/test/t/variant.cpp b/third_party/variant/test/t/variant.cpp
index 36655a501..b4322a26f 100644
--- a/third_party/variant/test/t/variant.cpp
+++ b/third_party/variant/test/t/variant.cpp
@@ -1,7 +1,7 @@
 #include "catch.hpp"
 
-#include "variant.hpp"
-#include "variant_io.hpp"
+#include <mapbox/variant.hpp>
+#include <mapbox/variant_io.hpp>
 
 #include <algorithm>
 #include <cstdint>
@@ -325,7 +325,7 @@ TEST_CASE("implicit conversion", "[variant][implicit conversion]")
 TEST_CASE("implicit conversion to first type in variant type list", "[variant][implicit conversion]")
 {
     using variant_type = mapbox::util::variant<long, char>;
-    variant_type var = 5.0; // converted to long
+    variant_type var = 5l; // converted to long
     REQUIRE(var.get<long>() == 5);
     REQUIRE_THROWS_AS({
         var.get<char>();
@@ -543,9 +543,9 @@ TEST_CASE("storing reference wrappers to consts works")
     int a = 1;
     variant_type v{std::cref(a)};
     REQUIRE(v.get<int const>() == 1);
-    REQUIRE(v.get<int>() == 1); // this works (see #82)
+    REQUIRE(v.get<int>() == 1);
     REQUIRE(mapbox::util::get<int const>(v) == 1);
-    //    REQUIRE(mapbox::util::get<int>(v) == 1); // this doesn't work (see #82)
+    REQUIRE(mapbox::util::get<int>(v) == 1);
     REQUIRE_THROWS_AS({
         v.get<double const>();
     },
@@ -568,3 +568,26 @@ TEST_CASE("storing reference wrappers to consts works")
     },
                       mapbox::util::bad_variant_access&);
 }
+
+TEST_CASE("recursive wrapper")
+{
+    using variant_type = mapbox::util::variant<mapbox::util::recursive_wrapper<int>>;
+    variant_type v(1);
+    REQUIRE(v.is<int>());
+    REQUIRE(v.get<int>() == 1);
+}
+
+
+TEST_CASE("variant : direct_type helper should match T, references (T&)  and const references (T const&) to the original type T)")
+{
+    using value = mapbox::util::variant<bool, std::uint64_t>;
+
+    std::uint64_t u(1234);
+    REQUIRE(value(u).is<std::uint64_t>()); // matches T
+
+    std::uint64_t& ur(u);
+    REQUIRE(value(ur).is<std::uint64_t>()); // matches T&
+
+    std::uint64_t const& ucr(u);
+    REQUIRE(value(ucr).is<std::uint64_t>()); // matches T const&
+}
diff --git a/third_party/variant/test/unique_ptr_test.cpp b/third_party/variant/test/unique_ptr_test.cpp
index 6578991ca..f07590003 100644
--- a/third_party/variant/test/unique_ptr_test.cpp
+++ b/third_party/variant/test/unique_ptr_test.cpp
@@ -6,9 +6,9 @@
 #include <typeinfo>
 #include <utility>
 
-#include <boost/timer/timer.hpp>
+#include "auto_cpu_timer.hpp"
 
-#include "variant.hpp"
+#include <mapbox/variant.hpp>
 
 using namespace mapbox;
 
@@ -112,7 +112,7 @@ int main(int argc, char** argv)
 
     int total = 0;
     {
-        boost::timer::auto_cpu_timer t;
+        auto_cpu_timer t;
         for (std::size_t i = 0; i < NUM_ITER; ++i)
         {
             total += util::apply_visitor(test::calculator(), result);
diff --git a/third_party/variant/variant.gyp b/third_party/variant/variant.gyp
index b1f3801f2..7d7dca8df 100644
--- a/third_party/variant/variant.gyp
+++ b/third_party/variant/variant.gyp
@@ -27,7 +27,7 @@
         "SUPPORTED_PLATFORMS":["macosx"]
       },
       "include_dirs": [
-          "./",
+          "./include",
           "test/include"
       ]
     }