Created a RAII class to switch LC_NUMERIC to "C" and back

src/libslic3r/LocalesUtils.hpp

@@ -0,0 +1,47 @@
+#ifndef slic3r_LocalesUtils_hpp_
+#define slic3r_LocalesUtils_hpp_
+
+#include <string>
+#include <clocale>
+#include <iomanip>
+#include <cassert>
+
+#ifdef __APPLE__
+#include <xlocale.h>
+#endif
+
+namespace Slic3r {
+
+// RAII wrapper that sets LC_NUMERIC to "C" on construction
+// and restores the old value on destruction.
+class CNumericLocalesSetter {
+public:
+    CNumericLocalesSetter();
+    ~CNumericLocalesSetter();
+
+private:
+#ifdef _WIN32
+    std::string m_orig_numeric_locale;
+#else
+    locale_t m_original_locale;
+    locale_t m_new_locale;
+#endif
+
+};
+
+// A function to check that current C locale uses decimal point as a separator.
+// Intended mostly for asserts.
+bool is_decimal_separator_point();
+
+
+// A substitute for std::to_string that works according to
+// C++ locales, not C locale. Meant to be used when we need
+// to be sure that decimal point is used as a separator.
+// (We use user C locales and "C" C++ locales in most of the code.)
+std::string float_to_string_decimal_point(double value, int precision = -1);
+std::string float_to_string_decimal_point(float value,  int precision = -1);
+
+
+} // namespace Slic3r
+
+#endif // slic3r_LocalesUtils_hpp_