diff options
| -rw-r--r-- | libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp | 64 |
1 files changed, 47 insertions, 17 deletions
diff --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp index b5362589963..0696c11526d 100644 --- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp +++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp @@ -10,7 +10,7 @@ // UNSUPPORTED: c++98, c++03, c++11, c++14 // <optional> -// template <class... Args> void optional<T>::emplace(Args&&... args); +// template <class... Args> T& optional<T>::emplace(Args&&... args); #include <optional> #include <type_traits> @@ -51,27 +51,35 @@ void test_one_arg() { using Opt = std::optional<T>; { Opt opt; - opt.emplace(); + auto & v = opt.emplace(); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); assert(*opt == T(0)); + assert(&v == &*opt); } { Opt opt; - opt.emplace(1); + auto & v = opt.emplace(1); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); assert(*opt == T(1)); + assert(&v == &*opt); } { Opt opt(2); - opt.emplace(); + auto & v = opt.emplace(); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); assert(*opt == T(0)); + assert(&v == &*opt); } { Opt opt(2); - opt.emplace(1); + auto & v = opt.emplace(1); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); assert(*opt == T(1)); + assert(&v == &*opt); } } @@ -83,20 +91,26 @@ void test_multi_arg() using Opt = std::optional<T>; { Opt opt; - opt.emplace(101, 41); + auto &v = opt.emplace(101, 41); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); + assert( v == T(101, 41)); assert(*opt == T(101, 41)); } { Opt opt; - opt.emplace({1, 2, 3, 4}); + auto &v = opt.emplace({1, 2, 3, 4}); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); - assert(*opt == T(4)); // T sets its value to the size of the init list + assert( v == T(4)); // T sets its value to the size of the init list + assert(*opt == T(4)); } { Opt opt; - opt.emplace({1, 2, 3, 4, 5}, 6); + auto &v = opt.emplace({1, 2, 3, 4, 5}, 6); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(static_cast<bool>(opt) == true); + assert( v == T(5)); // T sets its value to the size of the init list assert(*opt == T(5)); // T sets its value to the size of the init list } } @@ -109,73 +123,87 @@ void test_on_test_type() { assert(T::alive == 0); { T::reset_constructors(); - opt.emplace(); + auto &v = opt.emplace(); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::default_constructed == 1); assert(T::destroyed == 0); assert(static_cast<bool>(opt) == true); assert(*opt == T()); + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace(); + auto &v = opt.emplace(); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::default_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T()); + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace(101); + auto &v = opt.emplace(101); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::value_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T(101)); + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace(-10, 99); + auto &v = opt.emplace(-10, 99); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::value_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T(-10, 99)); + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace(-10, 99); + auto &v = opt.emplace(-10, 99); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::value_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T(-10, 99)); + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace({-10, 99, 42, 1}); + auto &v = opt.emplace({-10, 99, 42, 1}); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::value_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T(4)); // size of the initializer list + assert(&v == &*opt); } { T::reset_constructors(); - opt.emplace({-10, 99, 42, 1}, 42); + auto &v = opt.emplace({-10, 99, 42, 1}, 42); + static_assert( std::is_same_v<T&, decltype(v)>, "" ); assert(T::alive == 1); assert(T::constructed == 1); assert(T::value_constructed == 1); assert(T::destroyed == 1); assert(static_cast<bool>(opt) == true); assert(*opt == T(4)); // size of the initializer list + assert(&v == &*opt); } } @@ -210,8 +238,10 @@ int main() } { optional<const int> opt; - opt.emplace(42); + auto &v = opt.emplace(42); + static_assert( std::is_same_v<const int&, decltype(v)>, "" ); assert(*opt == 42); + assert( v == 42); opt.emplace(); assert(*opt == 0); } |
