fix usage formatting

diff --git a/main.cpp b/main.cpp
index 7062ec8b77ec938adcb06d8fe4bd675c7ba070ea..200839351267ff3f370a91a7241dda1580a30118 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -269,6 +269,7 @@ class OptionsParser final
         os << "Usage: " << argv0;
         for (auto &option : options.options)
         {
+            os << " ";
             if (!option.required)
             {
                 os << "[";