Merge pull request #216 from dosbox-staging/staging/locale-optional-1

Make the use of locale optional via `LOGURU_USE_LOCALE`

loguru.cpp

@@ -32,6 +32,7 @@
 
 #include <algorithm>
 #include <atomic>
+#include <cctype>
 #include <chrono>
 #include <cstdarg>
 #include <cstdio>
@@ -75,7 +76,6 @@
 
 // TODO: use defined(_POSIX_VERSION) for some of these things?
 
-
 #if defined(_WIN32) || defined(__CYGWIN__)
  #define LOGURU_PTHREADS 0
  #define LOGURU_WINTHREADS 1
@@ -472,7 +472,20 @@ namespace loguru
  for (int arg_it = 1; arg_it < argc; ++arg_it) {
  auto cmd = argv[arg_it];
  auto arg_len = strlen(verbosity_flag);
- if (strncmp(cmd, verbosity_flag, arg_len) == 0 && !std::isalpha(cmd[arg_len], std::locale(""))) {
+
+ bool last_is_alpha = false;
+ #if LOGURU_USE_LOCALE
+ try { // locale variant of isalpha will throw on error
+ last_is_alpha = std::isalpha(cmd[arg_len], std::locale(""));
+ }
+ catch (...) {
+ last_is_alpha = std::isalpha(static_cast<int>(cmd[arg_len]));
+ }
+ #else
+ last_is_alpha = std::isalpha(static_cast<int>(cmd[arg_len]));
+ #endif
+
+ if (strncmp(cmd, verbosity_flag, arg_len) == 0 && !last_is_alpha) {
  out_argc -= 1;
  auto value_str = cmd + arg_len;
  if (value_str[0] == '\0') {

loguru.hpp

@@ -175,6 +175,10 @@ Website: www.ilikebigbits.com
  #define LOGURU_USE_FMTLIB 0
 #endif
 
+#ifndef LOGURU_USE_LOCALE
+ #define LOGURU_USE_LOCALE 0
+#endif
+
 #ifndef LOGURU_WITH_FILEABS
  #define LOGURU_WITH_FILEABS 0
 #endif