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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <functional>
// template<class R, class ...Args>
// function(R(*)(Args...)) -> function<R(Args...)>;
// UNSUPPORTED: c++03, c++11, c++14
// UNSUPPORTED: libcpp-no-deduction-guides
#include <functional>
#include <type_traits>
#include "test_macros.h"
struct R { };
struct A1 { };
struct A2 { };
struct A3 { };
R f0() { return {}; }
R f1(A1) { return {}; }
R f2(A1, A2) { return {}; }
R f3(A1, A2, A3) { return {}; }
R f4(A1 = {}) { return {}; }
int main(int, char**) {
{
// implicit
std::function a = f0;
ASSERT_SAME_TYPE(decltype(a), std::function<R()>);
std::function b = &f0;
ASSERT_SAME_TYPE(decltype(b), std::function<R()>);
// explicit
std::function c{f0};
ASSERT_SAME_TYPE(decltype(c), std::function<R()>);
std::function d{&f0};
ASSERT_SAME_TYPE(decltype(d), std::function<R()>);
}
{
// implicit
std::function a = f1;
ASSERT_SAME_TYPE(decltype(a), std::function<R(A1)>);
std::function b = &f1;
ASSERT_SAME_TYPE(decltype(b), std::function<R(A1)>);
// explicit
std::function c{f1};
ASSERT_SAME_TYPE(decltype(c), std::function<R(A1)>);
std::function d{&f1};
ASSERT_SAME_TYPE(decltype(d), std::function<R(A1)>);
}
{
// implicit
std::function a = f2;
ASSERT_SAME_TYPE(decltype(a), std::function<R(A1, A2)>);
std::function b = &f2;
ASSERT_SAME_TYPE(decltype(b), std::function<R(A1, A2)>);
// explicit
std::function c{f2};
ASSERT_SAME_TYPE(decltype(c), std::function<R(A1, A2)>);
std::function d{&f2};
ASSERT_SAME_TYPE(decltype(d), std::function<R(A1, A2)>);
}
{
// implicit
std::function a = f3;
ASSERT_SAME_TYPE(decltype(a), std::function<R(A1, A2, A3)>);
std::function b = &f3;
ASSERT_SAME_TYPE(decltype(b), std::function<R(A1, A2, A3)>);
// explicit
std::function c{f3};
ASSERT_SAME_TYPE(decltype(c), std::function<R(A1, A2, A3)>);
std::function d{&f3};
ASSERT_SAME_TYPE(decltype(d), std::function<R(A1, A2, A3)>);
}
// Make sure defaulted arguments don't mess up the deduction
{
// implicit
std::function a = f4;
ASSERT_SAME_TYPE(decltype(a), std::function<R(A1)>);
std::function b = &f4;
ASSERT_SAME_TYPE(decltype(b), std::function<R(A1)>);
// explicit
std::function c{f4};
ASSERT_SAME_TYPE(decltype(c), std::function<R(A1)>);
std::function d{&f4};
ASSERT_SAME_TYPE(decltype(d), std::function<R(A1)>);
}
return 0;
}
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