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author | Anna Gringauze <annagrin@microsoft.com> | 2018-06-07 13:36:56 -0700 |
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committer | GitHub <noreply@github.com> | 2018-06-07 13:36:56 -0700 |
commit | cb2d1af89afb76bf50efe8e068c5ea1fc2872274 (patch) | |
tree | 88464c546dbcbcb1c093d3a19f47e0b080f99a51 | |
parent | 75ad0c1b40d27a2d0749861df923cb38f866a6c2 (diff) | |
download | platform_external_Microsoft-GSL-cb2d1af89afb76bf50efe8e068c5ea1fc2872274.tar.gz platform_external_Microsoft-GSL-cb2d1af89afb76bf50efe8e068c5ea1fc2872274.tar.bz2 platform_external_Microsoft-GSL-cb2d1af89afb76bf50efe8e068c5ea1fc2872274.zip |
Added template argument deduction for not_null (#689)
* Added template argument deduction for not_null
This allows compilers with c++17 support to infer template
instantiation types when calling not_null constructor:
int foo(not_null<const int*> x);
int main()
{
int t = 0;
not_null x{ &t };
return foo(not_null{ &t });
}
* replaced deduction guides by a simple constructor
* Updated tests
* fixed check for availability of std::byte
* testing c++1z on clang
* fixed cmakelists extra endif
* include cstddef header for clang and gcc in pointers
* fixed a typo
* fix missing nullptr_t type
* fixed typo in CMakeLists.tst
* change approach to c++17 testing, step one: revert cmake testing, update clang5.0 package
removed using latest c++ due to clang5.0 failing,
update clang5.0 travis config to use llvm-toolchain-trusty-5.0
* addressed comments
-rw-r--r-- | .travis.yml | 2 | ||||
-rw-r--r-- | CMakeLists.txt | 17 | ||||
-rw-r--r-- | include/gsl/pointers | 6 | ||||
-rw-r--r-- | tests/notnull_tests.cpp | 59 |
4 files changed, 80 insertions, 4 deletions
diff --git a/.travis.yml b/.travis.yml index 647a1c1..d2e4d9d 100644 --- a/.travis.yml +++ b/.travis.yml @@ -128,7 +128,7 @@ matrix: sources: - ubuntu-toolchain-r-test - llvm-toolchain-trusty-5.0 - - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-4.0 main' + - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-5.0 main' key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key' - env: COMPILER=clang++-5.0 BUILD_TYPE=Release diff --git a/CMakeLists.txt b/CMakeLists.txt index 0ab5e44..e96fb64 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -14,20 +14,31 @@ if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR) set(GSL_STANDALONE_PROJECT ON) endif () + +include(CheckCXXCompilerFlag) +if (NOT MSVC) + CHECK_CXX_COMPILER_FLAG("-std=c++14" COMPILER_SUPPORTS_CXX14) +else() + CHECK_CXX_COMPILER_FLAG("-std:c++14" COMPILER_SUPPORTS_CXX14) +endif() + # when minimum version required is 3.8.0 remove if below # both branches do exactly the same thing if (CMAKE_VERSION VERSION_LESS 3.7.9) if (NOT MSVC) - include(CheckCXXCompilerFlag) - CHECK_CXX_COMPILER_FLAG("-std=c++14" COMPILER_SUPPORTS_CXX14) if(COMPILER_SUPPORTS_CXX14) target_compile_options(GSL INTERFACE "-std=c++14") else() message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++14 support. Please use a different C++ compiler.") endif() + else() + if(COMPILER_SUPPORTS_CXX14) + target_compile_options(GSL INTERFACE "-std:c++14") + else() + message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++14 support. Please use a different C++ compiler.") + endif() endif() else () - # set the GSL library to be compiled only with c++14 target_compile_features(GSL INTERFACE cxx_std_14) # on *nix systems force the use of -std=c++XX instead of -std=gnu++XX (default) set(CMAKE_CXX_EXTENSIONS OFF) diff --git a/include/gsl/pointers b/include/gsl/pointers index ad15ce3..69499d6 100644 --- a/include/gsl/pointers +++ b/include/gsl/pointers @@ -77,6 +77,12 @@ public: Expects(ptr_ != nullptr); } + template <typename = std::enable_if_t<!std::is_same<std::nullptr_t, T>::value>> + constexpr explicit not_null(T u) : ptr_(u) + { + Expects(ptr_ != nullptr); + } + template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>> constexpr not_null(const not_null<U>& other) : not_null(other.get()) { diff --git a/tests/notnull_tests.cpp b/tests/notnull_tests.cpp index fa99bb7..1cb9c10 100644 --- a/tests/notnull_tests.cpp +++ b/tests/notnull_tests.cpp @@ -112,6 +112,7 @@ struct NonCopyableNonMovable }; bool helper(not_null<int*> p) { return *p == 12; } +bool helper_const(not_null<const int*> p) { return *p == 12; } TEST_CASE("TestNotNullConstructors") { @@ -328,4 +329,62 @@ TEST_CASE("TestNotNullCustomPtrComparison") CHECK((NotNull2(p2) >= NotNull1(p1)) == (p2 >= p1)); } + +#if defined(__cplusplus) && (__cplusplus >= 201703L) +TEST_CASE("TestNotNullConstructorTypeDeduction") +{ + { + int i = 42; + + not_null x{&i}; + helper(not_null{&i}); + helper_const(not_null{&i}); + + CHECK(*x == 42); + } + + { + int i = 42; + int* p = &i; + + not_null x{p}; + helper(not_null{p}); + helper_const(not_null{p}); + + CHECK(*x == 42); + } + + { + auto workaround_macro = []() { + int* p1 = nullptr; + not_null x{p1}; + }; + CHECK_THROWS_AS(workaround_macro(), fail_fast); + } + + { + auto workaround_macro = []() { + const int* p1 = nullptr; + not_null x{p1}; + }; + CHECK_THROWS_AS(workaround_macro(), fail_fast); + } + + { + int* p = nullptr; + + CHECK_THROWS_AS(helper(not_null{p}), fail_fast); + CHECK_THROWS_AS(helper_const(not_null{p}), fail_fast); + } + +#ifdef CONFIRM_COMPILATION_ERRORS + { + not_null x{nullptr}; + helper(not_null{nullptr}); + helper_const(not_null{nullptr}); + } +#endif +} +#endif // #if defined(__cplusplus) && (__cplusplus >= 201703L) + static_assert(std::is_nothrow_move_constructible<not_null<void *>>::value, "not_null must be no-throw move constructible"); |