as per 23.7.2.1:
- span() and span(nullptr) can only be used if extent is dynamic or 0
- span( element_type(&arr)[N] ) can only be used if extent is dynamic or N
- std::array can be used for initialization if extent is dynamic or size of the array
- Containers can be used for initialization if pointer type is convertible
as per 23.7.2.2
- first<N> and last<N> may no longer exceed the span extents
* rewrite span subspan checks to help optimizations
* Removed checking pointer for null for subspans. We would never
check pointer for null in between ptr and ptr+size in the
original span, so there seems to be no reason to do so for
subspans, provided that the subspan's boundaries are ensured
to be within the range of the original span's boundaries.
This change allows to simplify generated code, for example, to
remove 5 out of 9 branches in code generated from the following
by MSVC, and 4 out 8 branches in clang and gcc-generated code:
span<int> mysubspan(int* p, std::ptrdiff_t size, std::ptrdiff_t i)
{
if (p != nullptr)
{
span<int> s = { p, size };
return s.subspan(i);
}
return { nullptr };
}
Similar effects are achieved for dynamic subspans of static spans,
where in the following code we remove 2 out of 4 branchs in MSVC
and GCC-generated code:
int test_dynamic_subspan_of_static_span(std::ptrdiff_t i)
{
int x[] = { 0,1,2,3,4,5 };
span<int, 6> s = { x };
auto subspan = s.subspan(i);
return subspan.size();
}
Fixes#510.
* Constrain the converting constructor to not participate in overload resolution when IsConst is true, so that it is never a copy constructor.
* Use Default Member Initializers for span_iterator's data members so that the default constructor can be explicitly defaulted.
* Declare all members of span_iterator GSL_NOEXCEPT: they only throw when contract violations throw.
* Don't use & in operator-> since evil types may overload it.
Project files were not following the clang-format style. For people
using IDEs were clang-format is always run after a save this would
cause unwanted changes.
This commit only applies "clang-format -i" to files.
* Add value_type to span
Currently I'm working on project which involves a lot of `span`s and mocking via Google Mock. Unfortunately a lot of standard matchers requires `value_type` type definition inside container which `gsl::span` lacks.
This pull request add `value_type` type definition inside `gsl::span`
* Strip cv from value_type of span and span_iterator
* Nest "gsl" directory inside a new "include" directory.
* Cleanup the _MSC_VER conditionals a bit; use constexpr on VS2017+.
* Don't #define noexcept on non-Microsoft implementations.
* Workaround VS2017 bug in multi_span. (Also implement == and != for static_bounds_dynamic_range_t because I'm an EoP semantic soundness snob.)
Fixes#441.
