osrm-backend/third_party/variant/test/t/unary_visitor.cpp
2016-12-01 15:44:27 -08:00

128 lines
3.6 KiB
C++

#include "catch.hpp"
#include <mapbox/variant.hpp>
#include <mapbox/variant_io.hpp>
#include <string>
struct some_visitor
{
int var_;
some_visitor(int init)
: var_(init) {}
int operator()(int val) const
{
return var_ + val;
}
int operator()(double val) const
{
return var_ + int(val);
}
int operator()(const std::string&) const
{
return 0;
}
};
TEST_CASE("non-const visitor works on const variants", "[visitor][unary visitor]")
{
using variant_type = const mapbox::util::variant<int, double, std::string>;
variant_type var1(123);
variant_type var2(3.2);
variant_type var3("foo");
REQUIRE(var1.get<int>() == 123);
REQUIRE(var2.get<double>() == Approx(3.2));
REQUIRE(var3.get<std::string>() == "foo");
some_visitor visitor{1};
REQUIRE(mapbox::util::apply_visitor(visitor, var1) == 124);
REQUIRE(mapbox::util::apply_visitor(visitor, var2) == 4);
REQUIRE(mapbox::util::apply_visitor(visitor, var3) == 0);
}
TEST_CASE("const visitor works on const variants", "[visitor][unary visitor]")
{
using variant_type = const mapbox::util::variant<int, double, std::string>;
variant_type var1(123);
variant_type var2(3.2);
variant_type var3("foo");
REQUIRE(var1.get<int>() == 123);
REQUIRE(var2.get<double>() == Approx(3.2));
REQUIRE(var3.get<std::string>() == "foo");
const some_visitor visitor{1};
REQUIRE(mapbox::util::apply_visitor(visitor, var1) == 124);
REQUIRE(mapbox::util::apply_visitor(visitor, var2) == 4);
REQUIRE(mapbox::util::apply_visitor(visitor, var3) == 0);
}
TEST_CASE("rvalue visitor works on const variants", "[visitor][unary visitor]")
{
using variant_type = const mapbox::util::variant<int, double, std::string>;
variant_type var1(123);
variant_type var2(3.2);
variant_type var3("foo");
REQUIRE(var1.get<int>() == 123);
REQUIRE(var2.get<double>() == Approx(3.2));
REQUIRE(var3.get<std::string>() == "foo");
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, var1) == 124);
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, var2) == 4);
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, var3) == 0);
}
TEST_CASE("visitor works on rvalue variants", "[visitor][unary visitor]")
{
using variant_type = const mapbox::util::variant<int, double, std::string>;
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, variant_type{123}) == 124);
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, variant_type{3.2}) == 4);
REQUIRE(mapbox::util::apply_visitor(some_visitor{1}, variant_type{"foo"}) == 0);
}
struct total_sizeof
{
total_sizeof() : total_(0) {}
template <class Value>
int operator()(const Value&) const
{
total_ += int(sizeof(Value));
return total_;
}
int result() const
{
return total_;
}
mutable int total_;
}; // total_sizeof
TEST_CASE("changes in visitor should be visible", "[visitor][unary visitor]")
{
using variant_type = mapbox::util::variant<int, std::string, double>;
variant_type v;
total_sizeof ts;
v = 5.9;
REQUIRE(mapbox::util::apply_visitor(ts, v) == sizeof(double));
REQUIRE(ts.result() == sizeof(double));
}
TEST_CASE("changes in const visitor (with mutable internals) should be visible", "[visitor][unary visitor]")
{
using variant_type = const mapbox::util::variant<int, std::string, double>;
variant_type v{"foo"};
const total_sizeof ts;
REQUIRE(mapbox::util::apply_visitor(ts, v) == sizeof(std::string));
REQUIRE(ts.result() == sizeof(std::string));
}