From 17fcb0dd9df705f3b3f25283fdddee8fcb31f52b Mon Sep 17 00:00:00 2001
From: azeteg <martin@ncore.li>
Date: Tue, 20 Feb 2018 17:56:46 +0100
Subject: [PATCH] Update argparse.hpp

---
 argparse.hpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/argparse.hpp b/argparse.hpp
index e62ea15..8cce157 100644
--- a/argparse.hpp
+++ b/argparse.hpp
@@ -139,9 +139,9 @@ class ArgumentParser {
     }
 
     struct Argument {
-        Argument() : short_name(""), name(""), optional(true), fixed_nargs(0), fixed(true) {}
+        Argument() : short_name(""), name(""), optional(true), fixed_nargs(0), fixed(true), used(false) {}
         Argument(const String& _short_name, const String& _name, bool _optional, char nargs)
-                : short_name(_short_name), name(_name), optional(_optional) {
+                : short_name(_short_name), name(_name), optional(_optional), used(false) {
             if (nargs == '+' || nargs == '*') {
                 variable_nargs = nargs;
                 fixed = false;
@@ -153,6 +153,7 @@ class ArgumentParser {
         String short_name;
         String name;
         bool optional;
+        bool used;
         union {
             size_t fixed_nargs;
             char variable_nargs;
@@ -301,6 +302,8 @@ class ArgumentParser {
                                       .append(active_name),
                                   true);
                 active = arguments_[index_[el]];
+                arguments_[index_[el]].used = true;
+
                 // check if we've satisfied the required arguments
                 if (active.optional && nrequired > 0)
                     argumentError(String("encountered optional argument ")
@@ -416,7 +419,10 @@ class ArgumentParser {
         arguments_.clear();
         variables_.clear();
     }
-    bool exists(const String& name) const { return index_.count(delimit(name)) > 0; }
+    bool exists(const String& name) const {
+        auto it = index_.find(delimit(name));
+        return (it != index_.end()) && (arguments_[it->second].used);
+    }
     size_t count(const String& name) {
         // check if the name is an argument
         if (index_.count(delimit(name)) == 0) return 0;