use inline functions instead of macros in charset.h

src/charset.h

@@ -25,10 +25,10 @@
 #include <config.h>
 #endif
 
-#if defined(SUPPORTED_LOCALES) && defined(HAVE_ICONV_H)
-
 #include <string>
 
+#if defined(SUPPORTED_LOCALES) && defined(HAVE_ICONV_H)
+
 void init_current_locale();
 
 void utf_to_locale(std::string &);
@@ -42,16 +42,16 @@ void str_pool_locale_to_utf(char *&);
 
 #else
 
-#define init_current_locale();
+void init_current_locale() { }
 
-#define utf_to_locale(x);
-#define locale_to_utf(x);
+void utf_to_locale(std::string &) { }
+void locale_to_utf(std::string &) { }
 
-#define utf_to_locale_cpy(x) (x)
-#define locale_to_utf_cpy(x) (x)
+std::string &utf_to_locale_cpy(const std::string &s) { return s; }
+std::string &locale_to_utf_cpy(const std::string &s) { return s; }
 
-#define str_pool_utf_to_locale(x);
-#define str_pool_locale_to_utf(x);
+void str_pool_utf_to_locale(char *&) { }
+void str_pool_locale_to_utf(char *&) { }
 
 #endif // SUPPORTED_LOCALES && HAVE_ICONV_H