From e443fd79fda075f6b4db965f1f01e3bc9d8ba104 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Wed, 6 Jan 2016 01:48:34 +0100
Subject: [PATCH] type-traits(#985): better solution to detect string-like
 types

we need this to branch into lexical conversion, which
should always take precedence over a string conversion.

The existing solution overlooked both the conversion paths
for char*, as well as the fact that chars and c-strings
can be handled directly (pass-through) by lexical conversion
---
 research/try.cpp | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/research/try.cpp b/research/try.cpp
index 643d3a728..1a3dbefc4 100644
--- a/research/try.cpp
+++ b/research/try.cpp
@@ -112,21 +112,30 @@ stringz (P<X> ptr)
   namespace {
     
     using lib::meta::Strip;
-    using std::__or_;
-    using std::__and_;
+    using std::is_convertible;
+    using std::is_arithmetic;
+    using std::is_same;
     using std::__not_;
+    using std::__and_;
+    using std::__or_;
     
     template<typename T, typename U>
     struct is_basically
-      : std::is_same <typename Strip<T>::TypeReferred
-                     ,typename Strip<U>::TypeReferred>
+      : is_same <typename Strip<T>::TypeReferred
+                ,typename Strip<U>::TypeReferred>
+      { };
+    
+    template<typename X>
+    struct is_StringLike
+      : __or_< is_basically<X, string>
+             , is_convertible<X, const char*>
+             >
       { };
     
     template<typename X>
     struct can_lexical2string
-      : __or_< std::is_arithmetic<X>
-             , is_basically<X, string>
-             , is_basically<typename std::remove_all_extents<X>::type, char>
+      : __or_< is_arithmetic<X>
+             , is_StringLike<X>
              >
       { };
   }