I guess one msvc version might not support __has_include ?

googletest/include/gtest/internal/gtest-port.h

@@ -2248,6 +2248,20 @@ using StringView = ::std::string_view;
     // The case where absl is configured NOT to alias std::string_view is not
     // supported.
     #  endif  // __has_include(<string_view>) && __cplusplus >= 201703L
+  #else // well, what if __has_include is not supported by the compiler ? that may be the case with older msvc ?
+    #if __cplusplus >= 201703L
+    // Otherwise for C++17 and higher use std::string_view for Matcher<>
+    // specializations.
+    #   define GTEST_INTERNAL_HAS_STRING_VIEW 1
+    #include <string_view>
+    namespace testing {
+    namespace internal {
+    using StringView = ::std::string_view;
+    }  // namespace internal
+    }  // namespace testing
+    // The case where absl is configured NOT to alias std::string_view is not
+    // supported.
+    #endif
   # endif  // __has_include
 #endif  // GTEST_HAS_ABSL