From ea2f16d26411cc047c1280d7b54a95e37d149b75 Mon Sep 17 00:00:00 2001
From: Zhihao Yuan <lichray@gmail.com>
Date: Sat, 23 Nov 2019 13:35:43 -0600
Subject: [PATCH] Upgrade and describe supported toolchains

---
 .travis.yml          |  7 +++++++
 README.md            | 11 +++++++----
 include/argparse.hpp |  1 +
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 4f98d23..01c6545 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,13 @@ matrix:
       dist: bionic
       language: cpp
       compiler: gcc
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - g++-8
+      env: CXX=g++-8 CC=gcc-8
     - os: osx
       osx_image: xcode10.2
       language: cpp
diff --git a/README.md b/README.md
index 586eca5..bc29600 100644
--- a/README.md
+++ b/README.md
@@ -587,10 +587,13 @@ $ ./main fex
 baz
 ```
 
-## Supported Compilers
-* GCC >= 7.0.0
-* Clang >= 4.0
-* MSVC >= 2017
+## Supported Toolchains
+
+| Compiler             | Standard Library | Test Environment   |
+| :------------------- | :--------------- | :----------------- |
+| GCC >= 8.3.0         | libstdc++        | Ubuntu 18.04       |
+| Clang >= 7.0.0       | libc++           | Xcode 10.2         |
+| MSVC >= 14.16        | Microsoft STL    | Visual Studio 2017 |
 
 ## Contributing
 Contributions are welcome, have a look at the [CONTRIBUTING.md](CONTRIBUTING.md) document for more information.
diff --git a/include/argparse.hpp b/include/argparse.hpp
index 6bf6383..6ce6f83 100644
--- a/include/argparse.hpp
+++ b/include/argparse.hpp
@@ -30,6 +30,7 @@ SOFTWARE.
 #pragma once
 #include <algorithm>
 #include <any>
+#include <charconv>
 #include <cstdlib>
 #include <functional>
 #include <iostream>