[Boost-commit] svn:boost r83377 - sandbox/type_erasure/libs/type_erasure/doc

Subject: [Boost-commit] svn:boost r83377 - sandbox/type_erasure/libs/type_erasure/doc
From: steven_at_[hidden]
Date: 2013-03-09 16:45:57

Author: steven_watanabe
Date: 2013-03-09 16:45:57 EST (Sat, 09 Mar 2013)
New Revision: 83377
URL: http://svn.boost.org/trac/boost/changeset/83377

Log:
Clarify constraints on template parameters.
Text files modified: 
   sandbox/type_erasure/libs/type_erasure/doc/type_erasure.qbk |    12 +++++++++++-                            
   1 files changed, 11 insertions(+), 1 deletions(-)

Modified: sandbox/type_erasure/libs/type_erasure/doc/type_erasure.qbk
==============================================================================
--- sandbox/type_erasure/libs/type_erasure/doc/type_erasure.qbk	(original)
+++ sandbox/type_erasure/libs/type_erasure/doc/type_erasure.qbk	2013-03-09 16:45:57 EST (Sat, 09 Mar 2013)
@@ -256,7 +256,10 @@
 A primitive concept must be a specialization of a
 class template, with a static member function
 called `apply`, which will be executed when the
-function is dispatched by __call.
+function is dispatched by __call.  The template
+can only take template type parameters.  non-type
+template parameters and template template parameters
+are not allowed.
 
 The template parameters of the concept
 may involve placeholders.  The following are
@@ -331,6 +334,13 @@
     static void apply(const T&);
   };
 
+  // Wrong.  Template template parameters are not allowed.
+  template<template<class> class T>
+  struct foo5
+  {
+      static void apply(T<int>&);
+  };
+
 [endsect]
 
 [section:predef Predefined Concepts]