[Bug libstdc++/11400] New: std::search_n() makes assumptions about Size parameter

["sebor at roguewave dot com" <gcc-bugzilla at gcc dot gnu dot org>]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11400

           Summary: std::search_n() makes assumptions about Size parameter
           Product: gcc
           Version: 3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sebor at roguewave dot com
                CC: gcc-bugs at gcc dot gnu dot org

The only requirement on the Size template parameter of the std::search_n()
template is that it be convertible to integral type (25.1.9, p4). The converse
is not required to hold. The program below fails to compile due to unwarranted
assumptions in the libstdc++ implementation of the algorithm.

Regards
Martin

$ cat t.cpp; g++ -c t.cpp   
#include <algorithm>

struct Integral { operator int() const; };

namespace std {

template int* search_n (int*, int*, Integral, const int&);

}

/build/contrib/gcc-3.2/include/c++/3.2/bits/stl_algo.h: In function 
   `_ForwardIter std::search_n(_ForwardIter, _ForwardIter, _Integer, const 
   _Tp&) [with _ForwardIter = int*, _Integer = Integral, _Tp = int]':
t.cpp:7:   instantiated from here
/build/contrib/gcc-3.2/include/c++/3.2/bits/stl_algo.h:612: conversion from `
   int' to non-scalar type `Integral' requested
/build/contrib/gcc-3.2/include/c++/3.2/bits/stl_algo.h:617: no match for `-- 
   Integral&' operator