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std::string::assign
- From: Richard Kojedzinszky <krichy at tvnetwork dot hu>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 28 Aug 2012 11:29:55 +0200 (CEST)
- Subject: std::string::assign
Dear All,
I've a strange bug, I've attached a small source which shows my issue.
So, I am trying to assign a string containing an embedded \0 in it. You
will find that in test() I use std::string::assign to do this, but in two
cases the results are different.
Please see the output of the attached source, and let me know if I am
missing something, or it is a bug in g++/stdc++.
Of course, the third form in test() works as expected, but in my
assumption all should.
With this g++ it behaves bad:
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.1-2'
--with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--enable-gnu-unique-object --enable-plugin --enable-objc-gc
--with-arch-32=i586 --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.1 (Debian 4.7.1-2)
But with freebsd's g++:
$ g++ -v
Using built-in specs.
Target: amd64-undermydesk-freebsd
Configured with: FreeBSD/amd64 system compiler
Thread model: posix
gcc version 4.2.1 20070831 patched [FreeBSD]
It works fine.
Thanks in advance,
Kojedzinszky Richard
Euronet Magyarorszag Informatikai Zrt.
#include <iostream>
#include <string>
#include <cstring>
void test(const char *p)
{
std::string v;
v.assign(p, ::strlen(p)+1);
std::cerr << "v=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;
v.assign(p, 1);
std::cerr << "v=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;
v.assign(p);
v.append(1, '\0');
std::cerr << "a=" << static_cast<const void*>(v.c_str()) << " size=" << v.size() << std::endl;
}
int main()
{
std::string x = "";
test("");
test(x.c_str());
}