A little better build but I really need to clean this up and use a state machine to handle the process.

regtest.cpp

@@ -0,0 +1,26 @@
+#include <fmt/core.h>
+#include <regex>
+#include <string>
+
+using namespace fmt;
+using namespace std;
+
+int main(int argc, char *argv[]) {
+  smatch matches;
+  regex to_test(argv[1]);
+  string line(argv[2]);
+
+  if(argc != 3) {
+    println("USAGE: regtest <regex> <line>");
+  } else {
+    if(regex_match(line, matches, to_test)) {
+      println("MATCHED: ");
+
+      for(auto &match : matches) {
+        println("\t{}", match.str());
+      }
+    } else {
+      println("NO MATCH");
+    }
+  }
+}