--- Begin Message ---
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Subject: |
bizarre backtrace when trying to initialize std::map with std::pair array |
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Date: |
Wed, 27 Jun 2007 18:17:57 -0000 |
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User-agent: |
G2/1.0 |
I'm trying to initialize a std::map with an array of std::pair, but it
causes a sigsegv. I'm using GCC 3.4.6 on RHEL 4.4 x86_64.
My gdb backtrace, a snippet of stl_map.h, and my program are included
below. For better formatted display, see http://paste.collinslabs.com/?show=30.
Notice in particular the values of the parameters to the map
constructor and the insert_unique() function in frames #3 and #2,
respectively. Why is __first in the map constructor one thing, and
__first in the insert_unique function another?
1.
/* map.cpp */
2.
#include <iostream>
3.
#include <map>
4.
#include <string>
5.
#include <utility>
6.
#include <vector>
7.
8.
namespace {
9.
void f() {}
10.
void g() {}
11.
12.
typedef std::pair<std::string, void (*)()> mypair_t;
13.
14.
mypair_t pairs[] =
15.
{
16.
mypair_t("f", &f),
17.
mypair_t("g", &g)
18.
};
19.
}
20.
21.
int main()
22.
{
23.
std::map<std::string, void (*)()> mymap(pairs, pairs
+sizeof(pairs));
24.
}
25.
26.
27.
/* stl_map.h line 180-ish (libstdc++ 3.3.5) */
28.
template <typename _InputIterator>
29.
map(_InputIterator __first, _InputIterator __last)
30.
: _M_t(_Compare(), allocator_type())
31.
{ _M_t.insert_unique(__first, __last); }
32.
33.
/* gdb backtrace
34.
********************************************************************************
35.
#0 0x00000033448903a9 in std::basic_string<char,
std::char_traits<char>, std::\
36.
allocator<char> >::basic_string () from /usr/lib64/libstdc++.so.
6
37.
#1 0x00000000004012af in pair<std::string, void (*)()>
(this=0x7fbffff510,
38.
address@hidden)
39.
at /usr/lib/gcc/x86_64-redhat-linux/3.4.6/../../../../
include/c++/3.4.6/bit\
40.
s/stl_pair.h:90
41.
#2 0x0000000000401100 in std::_Rb_tree<std::string,
std::pair<std::string cons\
42.
t, void (*)()>, std::_Select1st<std::pair<std::string const,
void (*)()> >, std\
43.
::less<std::string>, std::allocator<std::pair<std::string const,
void (*)()> > \
44.
>::insert_unique<std::pair<std::string, void (*)()>*>
(this=0x7fbffff5d0,
45.
__first=0x502bc0, __last=0x502da0)
46.
at /usr/lib/gcc/x86_64-redhat-linux/3.4.6/../../../../
include/c++/3.4.6/bit\
47.
s/stl_tree.h:996
48.
#3 0x0000000000400faf in map<<unnamed>::mypair_t*>
(this=0x7fbffff5d0,
49.
__first=0x502ba0, __last=0x502da0)
50.
at /usr/lib/gcc/x86_64-redhat-linux/3.4.6/../../../../
include/c++/3.4.6/bit\
51.
s/stl_map.h:180
52.
#4 0x0000000000400d66 in main () at map.cpp:22
53.
*******************************************************************************
54.
*/
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