From 2676e172db018af7ef4bb93c274f18fd8319460d Mon Sep 17 00:00:00 2001
From: Duncan Horn <duncan.horn@utexas.edu>
Date: Fri, 10 Mar 2017 09:02:13 -0800
Subject: [PATCH] Updating length_func<CharT>::operator() to accept
 pointer-to-const. (#458)

---
 include/gsl/string_span | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/gsl/string_span b/include/gsl/string_span
index cd7f4b8..9e75ae8 100644
--- a/include/gsl/string_span
+++ b/include/gsl/string_span
@@ -217,7 +217,7 @@ namespace details
     template <>
     struct length_func<char>
     {
-        std::ptrdiff_t operator()(char* const ptr, std::ptrdiff_t length) GSL_NOEXCEPT
+        std::ptrdiff_t operator()(const char* const ptr, std::ptrdiff_t length) GSL_NOEXCEPT
         {
             return details::string_length(ptr, length);
         }
@@ -226,7 +226,7 @@ namespace details
     template <>
     struct length_func<wchar_t>
     {
-        std::ptrdiff_t operator()(wchar_t* const ptr, std::ptrdiff_t length) GSL_NOEXCEPT
+        std::ptrdiff_t operator()(const wchar_t* const ptr, std::ptrdiff_t length) GSL_NOEXCEPT
         {
             return details::wstring_length(ptr, length);
         }