[STDCXX-976] std::uninitialized_copy() requires InputIterator::operator*() returning lvalue

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.2.0, 4.2.1
• Fix Version/s: 4.2.2
• Component/s: 25. Algorithms

Environment

All

• Patch Info: Patch Available
• Regression: Regression
• Severity: Compiler Error
• Assignee: Farid Zaripov
• Reporter: Farid Zaripov
• Created: 27/Jun/08 10:51
• Updated: 02/May/13 02:29
• Resolved: 14/Oct/08 10:36

Description

The following test fails to compile:

#include <memory>
#include <iterator>

struct InputIterator: std::iterator<std::input_iterator_tag, char>
{
    const char *p_;

    InputIterator (const char *p): p_ (p) { }
    InputIterator (const InputIterator &rhs): p_ (rhs.p_) { }

    InputIterator& operator= (const InputIterator &rhs)
    { p_ = rhs.p_; return *this; }

    char operator* () const { return *p_; }
    
    InputIterator& operator++ () { return ++p_, *this; }
    InputIterator operator++ (int) {
        return ++p_, InputIterator (p_ - 1);
    }

    bool operator== (const InputIterator &rhs) const { return p_ == rhs.p_; }
    bool operator!= (const InputIterator &rhs) const { return p_ != rhs.p_; }
};

int main ()
{
    char src [5] = "abcd";
    char dst [5];

    std::uninitialized_copy (InputIterator (src), InputIterator (src + 5), dst);

    return 0;
}

D:\_Libs\stdcxx-4.2.2\include\rw\_specialized.h(168) : error C2665: '__rw::__rw_construct' : none of the 2 overloads can convert parameter 2 from type 'char'
        D:\_Libs\stdcxx-4.2.2\include\rw\_specialized.h(88): could be 'void __rw::__rw_construct<char,char>(_TypeT *,_TypeU &)'
        with
        [
            _TypeT=char,
            _TypeU=char
        ]
        D:\_Libs\stdcxx-4.2.2\include\rw\_specialized.h(96): or       'void __rw::__rw_construct<char,char>(volatile _TypeT *,_TypeU &)'
        with
        [
            _TypeT=char,
            _TypeU=char
        ]
        while trying to match the argument list '(char *, char)'
        test.cpp(29) : see reference to function template instantiation '_ForwardIterator std::uninitialized_copy<InputIterator,char*>(_InputIterator,_InputIterator,_ForwardIterator)' being compiled
        with
        [
            _ForwardIterator=char *,
            _InputIterator=InputIterator
        ]

The fix:

Index: include/rw/_specialized.h
===================================================================
--- include/rw/_specialized.h	(revision 671890)
+++ include/rw/_specialized.h	(working copy)
@@ -85,7 +85,7 @@
 
 template <class _TypeT, class _TypeU>
 inline void
-__rw_construct (_TypeT* __p, _TypeU& __val)
+__rw_construct (_TypeT* __p, const _TypeU& __val)
 {
     ::new (_RWSTD_STATIC_CAST (void*, __p)) _TypeT (__val);
 }
@@ -93,7 +93,7 @@
 
 template <class _TypeT, class _TypeU>
 inline void
-__rw_construct (volatile _TypeT* __p, _TypeU& __val)
+__rw_construct (volatile _TypeT* __p, const _TypeU& __val)
 {
     // remove volatile before invoking operator new
     __rw_construct (_RWSTD_CONST_CAST (_TypeT*, __p), __val);
@@ -103,7 +103,7 @@
 
 template <class _TypeT, class _TypeU>
 inline void
-__rw_construct_impl (_TypeT* __p, _TypeU& __val)
+__rw_construct_impl (_TypeT* __p, const _TypeU& __val)
 {
     ::new (_RWSTD_STATIC_CAST (void*, __p)) _TypeT (__val);
 }
@@ -111,7 +111,7 @@
 
 template <class _TypeT, class _TypeU>
 inline void
-__rw_construct (volatile _TypeT* __p, _TypeU& __val)
+__rw_construct (volatile _TypeT* __p, const _TypeU& __val)
 {
     // remove volatile before invoking operator new
     __rw_construct_impl (_RWSTD_CONST_CAST (_TypeT*, __p), __val);

Issue Links

• depends upon: STDCXX-1005 [HP aCC 3.73] ICE on +DD64 and partial specialization
• is related to: STDCXX-390 [HP aCC 3.73] error on std::uninitialized_copy<volatile T*, U>()