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// MPark.Variant
//
// Copyright Michael Park, 2015-2017
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <mpark/variant.hpp>
#include <cassert>
#include <string>
#include <sstream>
#include <gtest/gtest.h>
namespace lib = mpark::lib;
enum Qual { LRef, ConstLRef, RRef, ConstRRef };
struct get_qual {
constexpr Qual operator()(int &) const { return LRef; }
constexpr Qual operator()(const int &) const { return ConstLRef; }
constexpr Qual operator()(int &&) const { return RRef; }
constexpr Qual operator()(const int &&) const { return ConstRRef; }
}; // get_qual
TEST(Visit, MutVarMutType) {
mpark::variant<int> v(42);
// Check `v`.
EXPECT_EQ(42, mpark::get<int>(v));
// Check qualifier.
EXPECT_EQ(LRef, mpark::visit(get_qual(), v));
EXPECT_EQ(RRef, mpark::visit(get_qual(), lib::move(v)));
}
TEST(Visit, MutVarConstType) {
mpark::variant<const int> v(42);
EXPECT_EQ(42, mpark::get<const int>(v));
// Check qualifier.
EXPECT_EQ(ConstLRef, mpark::visit(get_qual(), v));
EXPECT_EQ(ConstRRef, mpark::visit(get_qual(), lib::move(v)));
}
TEST(Visit, ConstVarMutType) {
const mpark::variant<int> v(42);
EXPECT_EQ(42, mpark::get<int>(v));
// Check qualifier.
EXPECT_EQ(ConstLRef, mpark::visit(get_qual(), v));
EXPECT_EQ(ConstRRef, mpark::visit(get_qual(), lib::move(v)));
#if !defined(__GNUC__) || __GNUC__ >= 5
/* constexpr */ {
constexpr mpark::variant<int> cv(42);
static_assert(42 == mpark::get<int>(cv), "");
// Check qualifier.
static_assert(ConstLRef == mpark::visit(get_qual(), cv), "");
static_assert(ConstRRef == mpark::visit(get_qual(), lib::move(cv)), "");
}
#endif
}
TEST(Visit, ConstVarConstType) {
const mpark::variant<const int> v(42);
EXPECT_EQ(42, mpark::get<const int>(v));
// Check qualifier.
EXPECT_EQ(ConstLRef, mpark::visit(get_qual(), v));
EXPECT_EQ(ConstRRef, mpark::visit(get_qual(), lib::move(v)));
#if !defined(__GNUC__) || __GNUC__ >= 5
/* constexpr */ {
constexpr mpark::variant<const int> cv(42);
static_assert(42 == mpark::get<const int>(cv), "");
// Check qualifier.
static_assert(ConstLRef == mpark::visit(get_qual(), cv), "");
static_assert(ConstRRef == mpark::visit(get_qual(), lib::move(cv)), "");
}
#endif
}
struct concat {
template <typename... Args>
std::string operator()(const Args &... args) const {
std::ostringstream strm;
std::initializer_list<int>({(strm << args, 0)...});
return lib::move(strm).str();
}
};
TEST(Visit, Zero) { EXPECT_EQ("", mpark::visit(concat{})); }
TEST(Visit_Homogeneous, Double) {
mpark::variant<int, std::string> v("hello"), w("world!");
EXPECT_EQ("helloworld!", mpark::visit(concat{}, v, w));
#if !defined(__GNUC__) || __GNUC__ >= 5
/* constexpr */ {
constexpr mpark::variant<int, double> cv(101), cw(202), cx(3.3);
struct add_ints {
constexpr int operator()(int lhs, int rhs) const { return lhs + rhs; }
constexpr int operator()(int lhs, double) const { return lhs; }
constexpr int operator()(double, int rhs) const { return rhs; }
constexpr int operator()(double, double) const { return 0; }
}; // add
static_assert(303 == mpark::visit(add_ints{}, cv, cw), "");
static_assert(202 == mpark::visit(add_ints{}, cw, cx), "");
static_assert(101 == mpark::visit(add_ints{}, cx, cv), "");
static_assert(0 == mpark::visit(add_ints{}, cx, cx), "");
}
#endif
}
TEST(Visit_Homogeneous, Quintuple) {
mpark::variant<int, std::string> v(101), w("+"), x(202), y("="), z(303);
EXPECT_EQ("101+202=303", mpark::visit(concat{}, v, w, x, y, z));
}
TEST(Visit_Heterogeneous, Double) {
mpark::variant<int, std::string> v("hello");
mpark::variant<double, const char *> w("world!");
EXPECT_EQ("helloworld!", mpark::visit(concat{}, v, w));
}
TEST(Visit_Heterogenous, Quintuple) {
mpark::variant<int, double> v(101);
mpark::variant<const char *> w("+");
mpark::variant<bool, std::string, int> x(202);
mpark::variant<char, std::string, const char *> y('=');
mpark::variant<long, short> z(303L);
EXPECT_EQ("101+202=303", mpark::visit(concat{}, v, w, x, y, z));
}
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