From a885ee6eb4b4ba2f6648598c258dd97e7fc440db Mon Sep 17 00:00:00 2001
From: Bernhard Manfred Gruber <bernhardmgruber@gmail.com>
Date: Wed, 15 Dec 2021 12:14:49 +0100
Subject: [PATCH] switch unit tests to C++20 on MSVC and fix range support
 detection

---
 CMakeLists.txt                    |  1 +
 include/llama/ArrayIndexRange.hpp |  1 +
 include/llama/HasRanges.hpp       | 16 ++++++++++++++++
 include/llama/View.hpp            |  1 +
 include/llama/VirtualRecord.hpp   |  1 +
 include/llama/llama.hpp           |  1 +
 include/llama/macros.hpp          | 10 ----------
 7 files changed, 21 insertions(+), 10 deletions(-)
 create mode 100644 include/llama/HasRanges.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cd1033a32e..b6909f1f1c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,7 @@ if (BUILD_TESTING)
 	catch_discover_tests(tests)
 	source_group(TREE "${CMAKE_CURRENT_LIST_DIR}/tests" FILES ${testSources})
 	if (MSVC)
+		target_compile_features(tests PRIVATE cxx_std_20)
 		target_compile_options(tests PRIVATE /std:c++latest) # C++20 does not include ranges yet in MSVC, because the ABI is not finalized
 		target_compile_options(tests PRIVATE /permissive- /constexpr:steps10000000 /diagnostics:caret)
 	else()
diff --git a/include/llama/ArrayIndexRange.hpp b/include/llama/ArrayIndexRange.hpp
index 9539bbd892..4a3ea253a3 100644
--- a/include/llama/ArrayIndexRange.hpp
+++ b/include/llama/ArrayIndexRange.hpp
@@ -2,6 +2,7 @@
 
 #include "ArrayExtents.hpp"
 #include "Core.hpp"
+#include "HasRanges.hpp"
 
 #include <algorithm>
 #include <iterator>
diff --git a/include/llama/HasRanges.hpp b/include/llama/HasRanges.hpp
new file mode 100644
index 0000000000..0dfe25db67
--- /dev/null
+++ b/include/llama/HasRanges.hpp
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+// TODO(bgruber): clang 10-13 (libstdc++ from gcc 11.2) fail to compile this currently with the issue described here:
+// https://stackoverflow.com/questions/64300832/why-does-clang-think-gccs-subrange-does-not-satisfy-gccs-ranges-begin-functi
+// Intel LLVM compiler is also using the clang frontend
+#define CAN_USE_RANGES 0
+#if __has_include(<version>)
+#    include <version>
+#    if defined(__cpp_concepts) && defined(__cpp_lib_ranges) && (!defined(__clang__) || __clang_major__ >= 14)        \
+        && !defined(__INTEL_LLVM_COMPILER)
+#        undef CAN_USE_RANGES
+#        define CAN_USE_RANGES 1
+#    endif
+#endif
diff --git a/include/llama/View.hpp b/include/llama/View.hpp
index 5644b974bb..cacdf0a795 100644
--- a/include/llama/View.hpp
+++ b/include/llama/View.hpp
@@ -8,6 +8,7 @@
 #include "BlobAllocators.hpp"
 #include "Concepts.hpp"
 #include "Core.hpp"
+#include "HasRanges.hpp"
 #include "macros.hpp"
 #include "mapping/One.hpp"
 
diff --git a/include/llama/VirtualRecord.hpp b/include/llama/VirtualRecord.hpp
index 3d09c48f30..6e980fb572 100644
--- a/include/llama/VirtualRecord.hpp
+++ b/include/llama/VirtualRecord.hpp
@@ -4,6 +4,7 @@
 #pragma once
 
 #include "View.hpp"
+#include "HasRanges.hpp"
 
 #include <iosfwd>
 #include <type_traits>
diff --git a/include/llama/llama.hpp b/include/llama/llama.hpp
index beaf7a66e0..e420fb5551 100644
--- a/include/llama/llama.hpp
+++ b/include/llama/llama.hpp
@@ -41,6 +41,7 @@
 #include "Copy.hpp"
 #include "Core.hpp"
 #include "DumpMapping.hpp"
+#include "HasRanges.hpp"
 #include "Meta.hpp"
 #include "ProxyRefOpMixin.hpp"
 #include "Vector.hpp"
diff --git a/include/llama/macros.hpp b/include/llama/macros.hpp
index aae5182a68..b8cb31bb95 100644
--- a/include/llama/macros.hpp
+++ b/include/llama/macros.hpp
@@ -116,16 +116,6 @@
 /// Forces a copy of a value. This is useful to prevent ODR usage of constants when compiling for GPU targets.
 #define LLAMA_COPY(x) decltype(x)(x)
 
-// TODO(bgruber): clang 10 and 11 fail to compile this currently with the issue described here:
-// https://stackoverflow.com/questions/64300832/why-does-clang-think-gccs-subrange-does-not-satisfy-gccs-ranges-begin-functi
-// let's try again with clang 12
-// Intel LLVM compiler is also using the clang frontend
-#if(__has_include(<ranges>) && defined(__cpp_concepts) && !defined(__clang__) && !defined(__INTEL_LLVM_COMPILER))
-#    define CAN_USE_RANGES 1
-#else
-#    define CAN_USE_RANGES 0
-#endif
-
 // https://devblogs.microsoft.com/cppblog/optimizing-the-layout-of-empty-base-classes-in-vs2015-update-2-3/
 #if defined(_MSC_VER)
 #    define LLAMA_DECLSPEC_EMPTY_BASES __declspec(empty_bases)