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From: "vincenzo.innocente at cern dot ch" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/54268] New: std::string::reserve not consistent with std::vector::reserve Date: Wed, 15 Aug 2012 08:25:00 -0000 [thread overview] Message-ID: <bug-54268-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54268 Bug #: 54268 Summary: std::string::reserve not consistent with std::vector::reserve Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: vincenzo.innocente@cern.ch as the following test shows std::string::reserve change capacity (and relocates the underling array) even in case the argument is smaller than the current capacity. std::vector::reserve will instead only extend the capacity, never shirk it? Is this intended? IN any case in pretty conducing for the naive developer… cat stringReserve.cpp #include <cassert> #include <string> #include <vector> #include <iostream> int main() { { std::string foo,bar; foo.reserve(100); std::cout << foo.capacity() << std::endl; std::cerr << std::hex << (size_t) foo.c_str() << std::endl; foo.reserve(10); std::cout << foo.capacity()<< std::endl; std::cerr << (size_t) foo.c_str() << std::endl; bar.reserve(100); foo.reserve(50); std::cout << foo.capacity() << std::endl; std::cerr << (size_t) foo.c_str() << std::endl; } { std::vector<char> foo,bar; foo.reserve(100); std::cout << foo.capacity() << std::endl; std::cerr << std::hex << (size_t) (&foo.front()) << std::endl; foo.reserve(10); std::cout << foo.capacity() << std::endl; std::cerr << (size_t) (&foo.front()) << std::endl; bar.reserve(100); foo.reserve(50); std::cout << foo.capacity() << std::endl; std::cerr << (size_t) (&foo.front()) << std::endl; } } c++ -std=c++11 stringReserve.cpp ./a.out 100 7fd289c03938 10 7fd289c03ae8 50 7fd289c03b18 100 7fd289c03920 100 7fd289c03920 100 7fd289c03920
next reply other threads:[~2012-08-15 8:25 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-08-15 8:25 vincenzo.innocente at cern dot ch [this message] 2012-08-15 14:20 ` [Bug libstdc++/54268] " paolo.carlini at oracle dot com 2012-08-15 14:32 ` vincenzo.innocente at cern dot ch
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