This avoids propagating -std=c++14 as a compile option
Currently if you use less than CMake 3.8 and you install the project
`-std=c++14` gets added to the INTERFACE_COMPILE_OPTIONS. This forces
users to use C++ 14 or remove the property from the imported target.
The solution is to raise the minimum and use `cxx_std_14`
- Move all install logic inside gsl_install.cmake
- This makes reading the logic easier, and avoids the enable language
issue with `GNUInstallDirs` by having it included after the project
call
- Have all functions inside gsl_functions.cmake
- Use CMake idiom PROJECT_IS_TOP_LEVEL
- Update README.md
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.
Somewhere along the way, GSL's implementation of final_act and finally seems to have become way overthought. This PR is to re-simplify these facilities back to what C++ Core Guidelines C.30 said which is simple and clear and works. It just copies the invocable thing, and doesn't bother trying to optimize the copy. This should be fine, because we're typically passing something that's cheap to copy, often a stateless lambda.
The problem in #846 appears to be because finally looks like was originally written as a const&/&& overload (its state at the time that issue was opened)... to eliminate a copy when you invoke it with a temporary. If so, then the && was probably never intended to be a forwarder, but an rvalue reference that tripped over the horrid C++ syntax collision where a && parameter magically instead means a forwarding reference because the type happens to be a template parameter type here. So I suspect the original author was just trying to write an rvalue overload, and the forwarder that's there now was never intended at all.
GCC 4.8.0 - 7.0 has a bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480) involving specialization in a namespace enclosing the specialized template. This PR fixes an appearance of this bug in the span header.
Both checks for Expects(ExtentType::size() != dynamic_extent); in storage_type are always useless. storage_type<ExtentType> is only ever created with ExtentType == extent_type<Extent>, where Extent has type std::size_t and is the extent of the span.
Looking at extent_type<std::size_t Ext>::size():
- if Ext != dynamic_extent, then size() always returns Ext, and therefore size() != dynamic_extent
- if Ext == dynamic_extent, then size() returns extent_type<dynamic_extent>::size_. size_ can only be set via one of two constructors:
- constexpr explicit extent_type(size_type size), which already does the check in question
- constexpr explicit extent_type(extent_type<Other> ext) : size_(ext.size()), which simply relies on the other extent's size() method
So there is no way for ExtentType::size() == dynamic_extent.
This file uses std::exception, so it should include the appropriate header.
Normally it gets the STL's <exception> header included via the gsl/assert file, but this is skipped with _HAS_EXCEPTIONS=0. I understand _HAS_EXCEPTIONS is undocumented and unsupported, but regardless, the appropriate header should be included here.
Alternatively, gsl/narrow should be modified to support _HAS_EXCEPTIONS=0, like gsl/assert was. But I'm not proposing that change. <exception> does define std::exception even with _HAS_EXCEPTIONS=0.
In the implementation of gsl::narrow, there is a comparison `static_cast<U>(t) != u` which may be comparing two floats.
The comparison here is done purposefully to categorize ill effects of narrowing conversion, since the values being compared *should* be the same when compared with `operator==`.
Note, using #pragma GCC will suppress this warning for both GCC and Clang.
The following reserved identifiers are being used specifically to target certain MSVC constructs, so suppress the warning in VS 2022 (LLVM) "... is reserved because it starts with '_' followed by a capital letter":
- _Unchecked_type
- _Verify_range
- _Verify_offset
- _Unwrapped
- _Unwrap_when_unverified
- _Seek_to
- _Unchecked_begin
- _Unchecked_end
[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>
* Update pipeline build tag
The build status was still looking for a "master" branch, updated it to point to "main"
* Update ios.yml
* Update android.yml
* Update azure-pipelines.yml
* Update CONTRIBUTING.md
Here is the warning currently being produced:
CMake Warning (dev) at C:/Program Files/CMake/share/cmake-3.19/Modules/GNUInstallDirs.cmake:223 (message):
Unable to determine default CMAKE_INSTALL_LIBDIR directory because no
target architecture is known. Please enable at least one language before
including GNUInstallDirs.
Call Stack (most recent call first):
cmake/guidelineSupportLibrary.cmake:20 (include)
CMakeLists.txt:4 (include)
This warning is for project developers. Use -Wno-dev to suppress it.
I noted how I fixed the error. This is caused by GNUInstallDirs automatically executing code just by including it.
I also added -Werror=dev to the CI to ensure this never happens again.
Co-authored-by: Juan Ramos <juanr0911@gmail.com>
* Require Git for build tests only if installed GTest is not found
Cloning via Git is not the only path to obtain Google Test framework. In Linux,
using a system package manager is the preferred way, and gtest can be installed
through APK, APT, DNF, pacman, or many other. Now we make Git mandatory after
checking GTest existence.
See also: https://github.com/microsoft/GSL/pull/961#discussion_r548959056
* Support standalone tests
The patch makes possible to run auto-tests against globally installed GSL,
ignoring local headers. To do this, run CMake in the tests/ folder.
cmake -B build -S tests -DGSL_CXX_STANDARD=14
This feature should not break existing build recipes.
Co-authored-by: Nicholas Guriev <nicholas@guriev.su>
It's much nicer and less error prone to just use add_subdirectory to establish the include directory.
Hide the GNUInstallDirs module by placing it in the helper module. The intent being that the main CMakeLists.txt should have a little code as possible. So that readers can quickly understand the project.
Use include_guard() when available in cmake 3.10+
Co-authored-by: Juan Ramos <juanr0911@gmail.com>
* [cmake] Adding options for INSTALL and TEST (#964)
* [cmake] Adding GSL_INSTALL option
Not all consumers of GSL automatically want to have this install logic.
It's good practice to gate install logic behind an option.
For an example look at magic_enum:
https://github.com/Neargye/magic_enum/blob/master/CMakeLists.txt
If the client wants to install GSL they still can. But they should ask
for it by overriding GSL_INSTALL.
* Update cmake/guidelineSupportLibrary.cmake
added nl@eof
* Update CMakeLists.txt
* Update CMakeLists.txt
Co-authored-by: Juan Ramos <juanr0911@gmail.com>
Co-authored-by: Jordan Maples [MSFT] <49793787+JordanMaples@users.noreply.github.com>
* missing config line restored by moving GNUInstallDirs back to main file
Co-authored-by: hdf89shfdfs <31327577+hdf89shfdfs@users.noreply.github.com>
Co-authored-by: Juan Ramos <juanr0911@gmail.com>
* [cmake] Adding GSL_INSTALL option
Not all consumers of GSL automatically want to have this install logic.
It's good practice to gate install logic behind an option.
For an example look at magic_enum:
https://github.com/Neargye/magic_enum/blob/master/CMakeLists.txt
If the client wants to install GSL they still can. But they should ask
for it by overriding GSL_INSTALL.
* Update cmake/guidelineSupportLibrary.cmake
added nl@eof
* Update CMakeLists.txt
* Update CMakeLists.txt
Co-authored-by: Juan Ramos <juanr0911@gmail.com>
Co-authored-by: Jordan Maples [MSFT] <49793787+JordanMaples@users.noreply.github.com>
* Use CMAKE_CXX_STANDARD when available
If the use has provided the variable CMAKE_CXX_STANDARD use that instead of providing a default cache variable.
* Typo
