Finalize 1.8.4 release.

[ginac.git] / m4 / ax_cxx_compile_stdcxx.m4

diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4
index 51a35054d08ce1296f1acb98d70a943bdcebb4a5..a3d964c699aac74685d2407f3f01ad077d1a15a1 100644 (file)
--- a/m4/ax_cxx_compile_stdcxx.m4
+++ b/m4/ax_cxx_compile_stdcxx.m4
@@ -43,7 +43,7 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 14
+#serial 15
 
 dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
 dnl  (serial version number 13).
@@ -189,7 +189,11 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus < 201103L
+// MSVC always sets __cplusplus to 199711L in older versions; newer versions
+// only set it correctly if /Zc:__cplusplus is specified as well as a
+// /std:c++NN switch:
+// https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
+#elif __cplusplus < 201103L && !defined _MSC_VER
 
 #error "This is not a C++11 compiler"
 
@@ -480,7 +484,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus < 201402L
+#elif __cplusplus < 201402L && !defined _MSC_VER
 
 #error "This is not a C++14 compiler"
 
@@ -604,7 +608,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus < 201703L
+#elif __cplusplus < 201703L && !defined _MSC_VER
 
 #error "This is not a C++17 compiler"
 
@@ -970,7 +974,7 @@ namespace cxx17
 
 }  // namespace cxx17
 
-#endif  // __cplusplus < 201703L
+#endif  // __cplusplus < 201703L && !defined _MSC_VER
 
 ]])
 
@@ -983,7 +987,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_20], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus < 202002L
+#elif __cplusplus < 202002L && !defined _MSC_VER
 
 #error "This is not a C++20 compiler"
 
@@ -1000,6 +1004,6 @@ namespace cxx20
 
 }  // namespace cxx20
 
-#endif  // __cplusplus < 202002L
+#endif  // __cplusplus < 202002L && !defined _MSC_VER
 
 ]])