Clang cl (#762)

* 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:
bda3d6a428
97062933ac
0f4fb04bac
1b0c19afd1
a5739ea5f0

* 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

include/gsl/multi_span

@@ -37,7 +37,7 @@
 #include <type_traits> // for enable_if_t, remove_cv_t, is_same, is_co...
 #include <utility>
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 
 // turn off some warnings that are noisy about our Expects statements
 #pragma warning(push)
@@ -62,7 +62,7 @@
 // compiletime, so the compiler wouldn't have to warn indiscriminently, but
 // could check if the source value actually doesn't fit into the target type
 // and only warn in those cases.
-#if __GNUC__ > 6
+#if defined(__GNUC__) && __GNUC__ > 6
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
@@ -596,7 +596,6 @@ public:
     using sliced_type = static_bounds<RestRanges...>;
     using mapping_type = contiguous_mapping_tag;
 
-    constexpr static_bounds(const static_bounds&) noexcept = default;
     constexpr static_bounds() /*noexcept*/ = default;
 
     template <typename SourceType, typename TargetType, std::size_t Rank>
@@ -1887,6 +1886,8 @@ public:
         auto d = narrow_cast<size_type>(sizeof(OtherValueType) / sizeof(value_type));
 
         const size_type size = this->bounds().total_size() / d;
+
+        GSL_SUPPRESS(type.3) // NO-FORMAT: attribute
         return {const_cast<OtherValueType*>(reinterpret_cast<const OtherValueType*>(this->data())),
                 size,
                 bounds_type{resize_extent(this->bounds().index_bounds(), d),
@@ -2274,7 +2275,7 @@ general_span_iterator<Span> operator+(typename general_span_iterator<Span>::diff
 
 } // namespace gsl
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 #if _MSC_VER < 1910
 
 #undef constexpr
@@ -2285,7 +2286,7 @@ general_span_iterator<Span> operator+(typename general_span_iterator<Span>::diff
 
 #endif // _MSC_VER
 
-#if __GNUC__ > 6
+#if defined(__GNUC__) && __GNUC__ > 6
 #pragma GCC diagnostic pop
 #endif // __GNUC__ > 6