Added const to argv type for better interoperability. (#98)

* Added const to argv type for better interoperability.

* Fixed example and tests compilation

* Reverted changes to catch.hpp

include/cxxopts.hpp

@@ -922,7 +922,7 @@ namespace cxxopts
 
     inline
     void
-    parse(int& argc, char**& argv);
+    parse(int& argc, const char**& argv);
 
     inline
     OptionAdder
@@ -1018,7 +1018,7 @@ namespace cxxopts
     checked_parse_arg
     (
       int argc,
-      char* argv[],
+      const char* argv[],
       int& current,
       std::shared_ptr<OptionDetails> value,
       const std::string& name
@@ -1291,7 +1291,7 @@ void
 Options::checked_parse_arg
 (
   int argc,
-  char* argv[],
+  const char* argv[],
   int& current,
   std::shared_ptr<OptionDetails> value,
   const std::string& name
@@ -1385,7 +1385,7 @@ Options::parse_positional(std::vector<std::string> options)
 }
 
 void
-Options::parse(int& argc, char**& argv)
+Options::parse(int& argc, const char**& argv)
 {
   int current = 1;
 

src/example.cpp

@@ -26,7 +26,7 @@ THE SOFTWARE.
 
 #include "cxxopts.hpp"
 
-int main(int argc, char* argv[])
+int main(int argc, const char* argv[])
 {
   try
   {

test/options.cpp

@@ -8,7 +8,7 @@ class Argv {
   public:
 
   Argv(std::initializer_list<const char*> args)
-  : m_argv(new char*[args.size()])
+  : m_argv(new const char*[args.size()])
   , m_argc(args.size())
   {
     int i = 0;
@@ -26,7 +26,7 @@ class Argv {
     }
   }
 
-  char** argv() const {
+  const char** argv() const {
     return m_argv.get();
   }
 
@@ -36,8 +36,8 @@ class Argv {
 
   private:
 
-  std::vector<std::unique_ptr<char[]>> m_args;
-  std::unique_ptr<char*[]> m_argv;
+  std::vector<std::unique_ptr<const char[]>> m_args;
+  std::unique_ptr<const char*[]> m_argv;
   int m_argc;
 };
 
@@ -68,7 +68,7 @@ TEST_CASE("Basic options", "[options]")
     "--space",
   });
 
-  char** actual_argv = argv.argv();
+  const char** actual_argv = argv.argv();
   auto argc = argv.argc();
 
   options.parse(argc, actual_argv);
@@ -133,7 +133,7 @@ TEST_CASE("No positional", "[positional]")
 
   Argv av({"tester", "a", "b", "def"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
   options.parse(argc, argv);
 
@@ -183,7 +183,7 @@ TEST_CASE("Some positional explicit", "[positional]")
 
   Argv av({"tester", "--output", "a", "b", "c", "d"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   options.parse(argc, argv);
@@ -209,7 +209,7 @@ TEST_CASE("No positional with extras", "[positional]")
 
   Argv av({"extras", "--", "a", "b", "c", "d"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   auto old_argv = argv;
@@ -231,7 +231,7 @@ TEST_CASE("Empty with implicit value", "[implicit]")
 
   Argv av({"implicit", "--implicit", ""});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   options.parse(argc, argv);
@@ -248,7 +248,7 @@ TEST_CASE("Integers", "[options]")
 
   Argv av({"ints", "--", "5", "6", "-6", "0", "0xab", "0xAf", "0x0"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   options.parse_positional("positional");
@@ -274,7 +274,7 @@ TEST_CASE("Unsigned integers", "[options]")
 
   Argv av({"ints", "--", "-2"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   options.parse_positional("positional");
@@ -347,7 +347,7 @@ TEST_CASE("Floats", "[options]")
 
   Argv av({"floats", "--double", "0.5", "--", "4", "-4", "1.5e6", "-1.5e6"});
 
-  char** argv = av.argv();
+  const char** argv = av.argv();
   auto argc = av.argc();
 
   options.parse_positional("positional");
@@ -372,7 +372,7 @@ TEST_CASE("Invalid integers", "[integer]") {
 
     Argv av({"ints", "--", "Ae"});
 
-    char **argv = av.argv();
+    const char **argv = av.argv();
     auto argc = av.argc();
 
     options.parse_positional("positional");