add upstream 10.17

1 files changed, 32 insertions, 0 deletions

diff --git a/zen/legacy_compiler.cpp b/zen/legacy_compiler.cpp
new file mode 100644
index 00000000..3e3b7ba7
--- /dev/null
+++ b/zen/legacy_compiler.cpp
@@ -0,0 +1,32 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#include "legacy_compiler.h"
+#include <charconv>
+//1. including this one in string_tools.h blows up VC++:
+//  "An internal error has occurred in the compiler. (compiler file 'd:\agent\_work\1\s\src\vctools\Compiler\Utc\src\p2\p2symtab.c', line 2618)"
+//2. using inside PCH: "fatal error C1076: compiler limit: internal heap limit reached"
+
+
+#if __cpp_lib_to_chars
+    #error get rid of workarounds
+#endif
+
+double zen::from_chars(const char* first, const char* last)
+{
+    return std::strtod(std::string(first, last).c_str(), nullptr);
+}
+
+
+const char* zen::to_chars(char* first, char* last, double num)
+{
+    const size_t bufSize = last - first;
+    const int charsWritten = std::snprintf(first, bufSize, "%g", num);
+    //C99: returns number of chars written if successful, < 0 or >= bufferSize on failure
+
+    return 0 <= charsWritten && charsWritten < static_cast<int>(bufSize) ?
+           first + charsWritten : first;
+}