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

src/libslic3r/LocalesUtils.cpp

@@ -0,0 +1,59 @@
+#include "LocalesUtils.hpp"
+
+
+namespace Slic3r {
+
+
+CNumericLocalesSetter::CNumericLocalesSetter()
+{
+#ifdef _WIN32
+    _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+    m_orig_numeric_locale = std::setlocale(LC_NUMERIC, nullptr);
+    std::setlocale(LC_NUMERIC, "C");
+#else
+    m_original_locale = uselocale((locale_t)0);
+    m_new_locale = duplocale(m_original_locale);
+    m_new_locale = newlocale(LC_NUMERIC_MASK, "C", m_new_locale);
+    uselocale(m_new_locale);
+#endif
+}
+
+
+
+CNumericLocalesSetter::~CNumericLocalesSetter()
+{
+#ifdef _WIN32
+    std::setlocale(LC_NUMERIC, m_orig_numeric_locale)
+#else
+    uselocale(m_original_locale);
+    freelocale(m_new_locale);
+#endif
+}
+
+
+
+bool is_decimal_separator_point()
+{
+    char str[5] = "";
+    sprintf(str, "%.1f", 0.5f);
+    return str[1] == '.';
+}
+
+std::string float_to_string_decimal_point(double value, int precision/* = -1*/)
+{
+    assert(is_decimal_separator_point());
+    std::stringstream buf;
+    if (precision >= 0)
+        buf << std::fixed << std::setprecision(precision);
+    buf << value;
+    return buf.str();
+}
+
+std::string float_to_string_decimal_point(float value, int precision/* = -1*/)
+{
+    return float_to_string_decimal_point(double(value), precision);
+}
+
+
+} // namespace Slic3r
+