Fixed possible macro redefinition (#1892)

MinGW libstdc++ may define `NOMINMAX` unconditionally. This fixes the case when it is already defined.

diff --git a/examples/main/main.cpp b/examples/main/main.cpp
index ef9e75fab9fe2c0ef9d4d758036b81c7fb4c6c91..a051fcbc5caf5db0a502fc0f8351e57516b439d4 100644 (file)
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@@ -23,7 +23,9 @@
 #include <unistd.h>
 #elif defined (_WIN32)
 #define WIN32_LEAN_AND_MEAN
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 #include <windows.h>
 #include <signal.h>
 #endif