Closes issue #550, which highlighted overhead in not_null::get for larger types such as shared_ptr. Every call to get would return a copy of the contained value.
This PR implements Herb's suggestion for changing the return type of not_null::get. The not_null's value will now only be copied if it is "trivially copyable"; otherwise, it will be returned by const reference.
Note: this change also forces the returned copy to be const.
[SF.12: Prefer the quoted form of #include for files relative to the including file and the angle bracket form everywhere else](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Rs-incform)
Additionally changed #include order in `span` so that all `span_ext` is in the GSL include block and not in the STL include block.
Fixes issues #1025.
Co-authored-by: Werner Henze <w.henze@avm.de>
* move span specialization of 'at' to <gsl/span> and update the parameter to be taken by reference
* undid previous changes and acted upon decisions made in maintainer sync. Fixed tests failing in /kernel mode
* ran clang-format on the include folder
* ran clang-format on the test folder
Co-authored-by: Jordan Maples <jordan.maples@microsoft.com>
* is_comparable_to_nullptr for better static_assert
Trying `gsl::not_null<char> p2{ 0 };` on VS2019 the current implementation would trigger
>error C2446 : '!=' : no conversion from 'nullptr' to 'int'
>message: A native nullptr can only be converted to bool or , using reinterpret_cast, to an integral type
>message: see reference to class template instantiation 'gsl::not_null<char>' being compiled
>error C2955 : 'std::is_convertible' : use of class template requires template argument list
>message: see declaration of 'std::is_convertible'
>error C2039 : 'value' : is not a member of 'std::is_convertible<_From,_To>'
>error C2065 : 'value' : undeclared identifier
The new implementation gives much shorter and clearer message and does exactly as the `static_assert` intends to do:
> error C2338: T cannot be compared to nullptr.
> message : see reference to class template instantiation 'gsl::not_null<char *>' being compiled
* Update include/gsl/pointers
Co-authored-by: Casey Carter <cartec69@gmail.com>
Co-authored-by: Werner Henze <w.henze@avm.de>
Co-authored-by: Casey Carter <cartec69@gmail.com>
* Added c++17 test configurations for clang5.0 and clang6.0
* Fix#739 correct cppcorecheck warnings for clang-cl
* Add clang-cl configurations
* Corrections Appveyor;
Temporarily disable msvc compilation for faster testing (#741)
* Add path to clang-cl.exe (#741)
* Escape backslash in path (#741)
* Update vcpkg (#741)
* Check vcpkg version; try without building vcpkg; use latest clang-cl from path (#741)
* Fix blocks in ps script (#741)
* Try accessing APPVEYOR_BUILD_FOLDER variable (#471)
* Update span size() bug confirmation test for GCC 6.5 (#741)
* MSVC flags to Clang-cl; disable c++98-compat and undefined macro warnings (#741)
* Suppress clang warning on tests (missing-prototypes) (#741)
* Fix clang warning -Wnewline-eof (#741)
* Fix clang warning -Wdouble-promotion (#741)
* Set linker explicitly
* Clean condition statement
* For Clang, fallback to the AppVeyor installed version of CMake
* Fix clang warning -Wmissing-variable-declarations
* Fallback to the MSVC linker until vcpkg has been updated
* Revert "Fallback to the MSVC linker until vcpkg has been updated"
This reverts commit 7263f3289e.
* Fix clang warning -Wunused-member-function
* Fix clang warning -Wmissing-noreturn
* Fix clang warning -Winvalid-noreturn on Windows
* Add macro block end comment on large #if blocks
* Workaround: fallback to mscv link.exe
* Workaround: get msvc paths into PowerShell through intermediate file
* Workaround: fix, remove "PATH=" from text
* Workaround: try with full-path; and return user PATH
* Workaround: fix, escape backslashes
* Revert all since "Workaround: fallback to mscv link.exe" did not work on AppVeyor
This reverts the commits:
bda3d6a42897062933ac0f4fb04bac1b0c19afd1a5739ea5f0
* Suppress output of git pull; remove vcpkg from cache
* Re-enable AppVeyor builds for all platforms
* Correct typo
Co-Authored-By: Farwaykorse <Farwaykorse@users.noreply.github.com>
* Add Clang-cl 7.0.0 to the supported platforms
* Revert "Fix clang warning -Wunused-member-function"
This reverts commit 6fe1a42035.
* Fix or locally suppress clang warning -Wunused-member-function
* format touched code and correct comment
* git pull --quiet
* fix logic error in workaround
* fix missing bracket
* Suppress output of mkdir
* Replace MSBuild with Ninja
* Suppress output of 7z
* Add architecture flags for Clang
* Drop workaround for lld-link
* 7-zip Overwrite and Alternative output suppression without suppressing errors
Replaces 3c1c0794dd
* AppVeyor setup and CMake before build
* reorder compiler configuration
* remove unnecessary
* remove -fno-strict-aliasing
* remove -Wsign-conversion, since before v4.0 part of -Wconversion
* -Wctor-dtor-privacy is GCC only
* remove -Woverloaded-virtual part of -Wmost, part of -Wall
* add -Wmissing-noreturn
* remove the pragmas for -Wunused-member-function
* Re-add MSBuild generator on AppVeyor
* Print CMake commands
* Add MSBuild toolset selection
* Separate Architecture setting
* clang-cl: add -Weverything
* clang-cl -Wno-c++98-compat
* clang-cl -Wno-c++98-compat-pedantic
* clang-cl -Wno-missing-prototypes
* clang-cl C++14 -Wno-unused-member-function
* clang-cl -Wundef __GNUC__
* clang++: add -Weverything
* clang++ -Wno-c++98-compat
* clang++ -Wno-c++98-compat-pedantic
* clang++ -Wno-missing-prototypes
* clang++ -Wno-weak-vtables
* clang++ C++14 -Wno-unused-member-function
* clang++ fix -Wundef _MSC_VER
* clang++ -Wno-padded
* clang++ solve -Wdeprecated
* Add AppleClang compiler target
Since CMake v3.0 use of Clang for both is deprecated
* clang++ v5.0 C++17 -Wno-undefined-func-template
* Add VS2015 + LLVM/clang-cl to AppVeyor
* Do not disable constexpr when compiling with clang-cl on Windows
* Clean-up clang-only warnings (now under -Weverything)
* Revert "Fix clang warning -Winvalid-noreturn on Windows"
This reverts commit 2238c4760e.
* Suppress -Winvalid-noreturn for the MS STL noexception workaround
* CMake: put preprocessor definition in target_compile_definitions
* Solve compiler warning C4668: __GNUC__ not defined
* Added c++17 test configurations for clang5.0 and clang6.0
* Removed explicit not_null constructor, sloppy_not_null, added strict_not_null
We added explicit not_null constructor in version 2.0.0.
It proved very difficult to switch to the new version for
large code bases that adopted previous versions of gsl,
due to not_null used extensively in the code. Still, using
explicit constructor is very benefitial for new code, since
it encorages better API design and make null checks intentional.
To resolve the issue, this change:
- removes explicit keyword from not_null constructor
- removes unneded sloppy_not_null type
- adds strict_not_null type to behave the same way as v2 not_null
- updates tests
* Removed explicit not_null constructor, sloppy_not_null, added strict_not_null
We added explicit not_null constructor in version 2.0.0.
It proved very difficult to switch to the new version for
large code bases that adopted previous versions of gsl,
due to not_null used extensively in the code. Still, using
explicit constructor is very benefitial for new code, since
it encorages better API design and make null checks intentional.
To resolve the issue, this change:
- removes explicit keyword from not_null constructor
- removes unneded sloppy_not_null type
- adds strict_not_null type to behave the same way as v2 not_null
- updates tests
* fixed build break for gcc7
* added more tests
* added more non-compiling tests
* Addressed PR comments and suppressed a code analysis warning
* Fixed test failure in not_null tests
* Added c++17 test configurations for clang5.0 and clang6.0
* Added make_not_null helper to create a not_null
Introduction of explicit not_null constructor made it cumbersome to create not_nulls
in c++14. Adding make_not_null helper. Usage (see tests):
int i = 42;
auto x = make_not_null(&i);
helper(make_not_null(&i));
helper_const(make_not_null(&i));
* Added std::forward to make_not_null, fixed some code analysis warnings
* Fix build break in VS2015 Release configuration
* Fix build break in VS2015 Release configuration
* 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
