add example to readme

README.md

@@ -3,7 +3,9 @@
 [![Build Status](https://travis-ci.com/cwpearson/argparse.svg?branch=master)](https://travis-ci.com/cwpearson/argparse)
 
 Simple single-file header-only CLI option parsing for C++.
-No subcommands, grouped commands.
+No subcommands or grouped commands.
+Only supports `-s value`/`--long-option value` style for options.
+Only supports `--long-flag` style for flags.
 
 ## Getting Started
 
@@ -18,16 +20,66 @@ Download the latest [`argparse.hpp`](www.google.com) and include it in your proj
 - [x] positional arguments
 - [x] `--` to stop parsing options and flags
 - [x] modify `argc`/`argv` (disable with `Parser::no_consume()`)
-- Option Types
+- Option/Positional Argument Types
   - [x] `int`
   - [x] `size_t`
   - [x] `float`
   - [x] `double`
   - [x] `std::string`
 
+## Examples
+
+```c++
+#include "argparse/argparse.hpp"
+
+int main(int argc, char **argv) {
+
+  // A parser object
+  Parser p;
+
+  // Program data corresponding to flags, options, and positional arguments
+  bool verbose = false;
+  std::string toPrint;
+  std::string maybePrint;
+  int repeats = 1;
+
+  // Inform the parser of the program data.
+  // It will do type-specific conversion
+  p.add_option(repeats, "--repeat");
+  p.add_flag(verbose, "--verbose", "-v");
+  p.add_positional(toPrint)->required();
+  auto psnl = p.add_positional(maybePrint);
+
+  // If there was an error during parsing, report it.
+  if (!p.parse(argc, argv)) {
+    std::cerr << p.help();
+    exit(EXIT_FAILURE);
+  }
+
+  // Execute the program logic
+  if (verbose) {
+    std::cerr << "about to print '" << toPrint << "' " << repeats << " times";
+    if (psnl->found()) {
+      std::cerr << ", then '" << maybePrint << "'";      
+    }
+    std::cerr << std::endl;
+  }
+
+  for (int i = 0; i < repeats; ++i) {
+    std::cout << toPrint;
+  }
+  if (psnl->found()) {
+    std::cout << maybePrint;
+  }
+  std::cout << std::endl;
+
+  return 0;
+}
+```
+
 ## Roadmap
 
-- [ ] examples
+- [ ] Reject duplicate flags / options
 - [ ] Help string output
 - [ ] support --long-option=value
 - [ ] have the last positional argument fill a vector with remaining