Two warnings were being emitted in the MSVC+LLVM tests.
The warning `-Wunsafe-buffer-usage` is initially introduced in some capacity here https://reviews.llvm.org/D137346 pointing to documentation at https://discourse.llvm.org/t/rfc-c-buffer-hardening/65734. The warning is a stylistic checker whose goal is to "emit a warning every time an unsafe operation is performed on a raw pointer". This type of programming model is not useful for library implementations of types such as `span`, where direct manipulation of raw pointers is inevitable, so disable the warning altogether.
There is also a false-positive warning https://github.com/llvm/llvm-project/issues/65689 that I've disabled inline.
Without this change a `gsl::not_null<class_type>` triggers these `noexcept` warnings:
```
.../gsl/include/gsl/pointers:162:50: warning: noexcept-expression evaluates to ‘false’ because of a call to ‘constexpr gsl::details::value_or_reference_return_t<T> gsl::not_null<T>::get() const [with T = class_type*; gsl::details::value_or_reference_return_t<T> = class_type* const]’ [-Wnoexcept]
162 | const not_null<U>& rhs) noexcept(noexcept(lhs.get() == rhs.get()))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../gsl/include/gsl/pointers:119:55: note: but ‘constexpr gsl::details::value_or_reference_return_t<T> gsl::not_null<T>::get() const [with T = class_type*; gsl::details::value_or_reference_return_t<T> = class_type* const]’ does not throw; perhaps it should be declared ‘noexcept’
119 | constexpr details::value_or_reference_return_t<T> get() const
| ^~~
```
Co-authored-by: Werner Henze <w.henze@avm.de>
Headers that were previously prefixed with `gsl_` were renamed to drop the `gsl_` prefix in https://github.com/microsoft/GSL/pull/946, and the original version deprecated.
The deprecation happened a long time ago, so it is now time to remove these headers entirely.
Using `<`,`<=`,`>`,`>=` to compare unrelated pointers gives an unspecified result according to the standard.
This PR replaces the usage of these operators in `gsl::not_null` with the STL counterparts, which would leverage any implementation-defined strict total ordering for pointers.
Resolves#880
`size_bytes()` returns the span's size in bytes.
Assuming the span was constructed with an accurate size parameter, the check `size() < dynamic_extent / sizeof(element_type)` isn't required, since `size_t(-1)` (which is `dynamic_extent`) represents the size of the address space, so the number of bytes will never exceed it and in practice won't even come close.
Otherwise, it is not actually feasible to detect cases when the size parameter does not correspond to the dimensions of the underlying data pointer. In these cases, the relationship `size() < dynamic_extent / sizeof(element_type)` is simply one of many ways in which the `size()` could be incorrect, and serves no necessary purpose.
Resolves#1012
https://github.com/microsoft/GSL/issues/1075
- Add `static_assert` because we only support C style array `at` for up to half of the address space.
- Add `std::` before `size_t`.
- tests:
- Add `#include <exception>`
- Implement `span_tests` `interop_with_gsl_at` like `at_tests` `std_span`
This solves issue #1070 and removes the class `string_span`. The only content remaining in the header file `gsl/string_span` is the `*zstring` types.
This also removes the `string_span_tests.cpp` unit tests as these were only for the deprecated `string_span` class.
Co-authored-by: Werner Henze <werner.henze+gitcommits@posteo.de>
Guidelines issue 2006 removes the null check inside not_null::get, since the contained pointer is already guaranteed to be not-null upon construction.
Resolves#1051
- 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.
* 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>
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>
* Azure pipeline (#8)
* azure-pipeline test
* nl @ eof
* trimming the pipeline and adding debug steps
* removing redundant lines
* change ctest to script cmd and remove debug
* removed bad char
* added dir change for ctest
* explicit output file and cmake standard
* test cat
* more ctest tests
* injecting failure in test for validation
* another test
* removing bad test
* massive matrix
* added parallel
* commenting everything but xcode out for testing purposes
* uncomment the other tests
* testing some variables
* rename
* changed macos versions
* adding one more layer of templates
* fixing jobs.yml
* idk what i'm doing
* slight modifications
* maybe some spaces will help
* removing 'variables.'
* another test
* adding back pr w/ autocancel
* adding failing test to validate error = failing task
* remove failing test
* trigger master
* nl in steps.yml
* removing deprecation of basic_zstring and derived types. only *string_span should have been deprecated
* Azure pipeline (#8)
* azure-pipeline test
* nl @ eof
* trimming the pipeline and adding debug steps
* removing redundant lines
* change ctest to script cmd and remove debug
* removed bad char
* added dir change for ctest
* explicit output file and cmake standard
* test cat
* more ctest tests
* injecting failure in test for validation
* another test
* removing bad test
* massive matrix
* added parallel
* commenting everything but xcode out for testing purposes
* uncomment the other tests
* testing some variables
* rename
* changed macos versions
* adding one more layer of templates
* fixing jobs.yml
* idk what i'm doing
* slight modifications
* maybe some spaces will help
* removing 'variables.'
* another test
* adding back pr w/ autocancel
* adding failing test to validate error = failing task
* remove failing test
* trigger master
* nl in steps.yml
* remove forced decay of array reference to pointer in span array ctor
