| // { dg-options "-std=gnu++2b" } |
| // { dg-do compile { target c++23 } } |
| |
| #include <functional> |
| |
| #ifndef __cpp_lib_invoke_r |
| # error Feature-test macro for invoke_r is missing in <functional> |
| #elif __cpp_lib_invoke_r < 202106L |
| # error Feature-test macro for invoke_r has the wrong value in <functional> |
| #endif |
| |
| constexpr int sq(int i) { return i * i; } |
| |
| template<typename Val, typename Expected> |
| constexpr bool chk(Val&& val, Expected&& exp) |
| { |
| return std::is_same_v<Val, Expected> && val == exp; |
| } |
| |
| void |
| test01() |
| { |
| static_assert( chk( std::invoke(sq, 2), 4 ) ); |
| static_assert( chk( std::invoke_r<int>(sq, 3), 9 ) ); |
| static_assert( chk( std::invoke_r<char>(sq, 4), '\x10' ) ); |
| } |
| |
| struct abstract { |
| virtual ~abstract() = 0; |
| void operator()() noexcept; |
| }; |
| |
| static_assert( noexcept(std::invoke(std::declval<abstract>())), |
| "It should be possible to use abstract types with INVOKE" ); |
| |
| static_assert( noexcept(std::invoke_r<void>(std::declval<abstract>())), |
| "It should be possible to use abstract types with INVOKE<R>" ); |
| |
| struct F { |
| void operator()() &; |
| void operator()() && noexcept; |
| int operator()(int); |
| double* operator()(int, int) noexcept; |
| }; |
| struct D { D(void*); }; |
| |
| static_assert( !noexcept(std::invoke(std::declval<F&>())) ); |
| static_assert( noexcept(std::invoke(std::declval<F>())) ); |
| static_assert( !noexcept(std::invoke(std::declval<F>(), 1)) ); |
| static_assert( noexcept(std::invoke(std::declval<F>(), 1, 2)) ); |
| |
| static_assert( !noexcept(std::invoke_r<void>(std::declval<F&>())) ); |
| static_assert( noexcept(std::invoke_r<void>(std::declval<F>())) ); |
| static_assert( !noexcept(std::invoke_r<int>(std::declval<F>(), 1)) ); |
| static_assert( !noexcept(std::invoke_r<void>(std::declval<F>(), 1)) ); |
| static_assert( !noexcept(std::invoke_r<long>(std::declval<F>(), 1)) ); |
| static_assert( noexcept(std::invoke_r<void>(std::declval<F>(), 1, 2)) ); |
| static_assert( noexcept(std::invoke_r<void*>(std::declval<F>(), 1, 2)) ); |
| static_assert( !noexcept(std::invoke_r<D>(std::declval<F>(), 1, 2)) ); |