Create example_usage.md

Author: janwilmans

doc/example_usage.md

@@ -0,0 +1,32 @@
+
+# An {fmt} wrapper around OutputDebugString makes sending formatted message much more plesant.
+```
+#include <fmt/format.h>
+
+#include <sstream>
+#include <string_view>
+
+void OutputDebugString(const char * message)
+{
+    fmt::print("{}", message);
+}
+
+void DebugMessage(std::string_view message)
+{
+    OutputDebugString(message.data());
+}
+
+template <typename... Args>
+void DebugMessage(std::string_view format, Args &&... args)
+{
+    auto formatted = fmt::vformat(format, fmt::make_args_checked<Args...>(format, std::forward<Args>(args)...));
+    OutputDebugString(formatted.data());
+}
+
+int main()
+{
+    DebugMessage("test");
+    DebugMessage("[{}]", 42);
+    return 0;
+}
+```