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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <ostream>
// template <class charT, class traits = char_traits<charT> >
// class basic_ostream;
// basic_ostream<charT,traits>& seekp(pos_type pos);
#include <ostream>
#include <cassert>
int seekpos_called = 0;
template <class CharT>
struct testbuf
: public std::basic_streambuf<CharT>
{
typedef std::basic_streambuf<CharT> base;
testbuf() {}
protected:
typename base::pos_type
seekpos(typename base::pos_type sp, std::ios_base::openmode which)
{
++seekpos_called;
assert(which == std::ios_base::out);
return sp;
}
};
int main()
{
{
seekpos_called = 0;
std::ostream os((std::streambuf*)0);
assert(&os.seekp(5) == &os);
assert(seekpos_called == 0);
}
{
seekpos_called = 0;
testbuf<char> sb;
std::ostream os(&sb);
assert(&os.seekp(10) == &os);
assert(seekpos_called == 1);
assert(os.good());
assert(&os.seekp(-1) == &os);
assert(seekpos_called == 2);
assert(os.fail());
}
{ // See https://bugs.llvm.org/show_bug.cgi?id=21361
seekpos_called = 0;
testbuf<char> sb;
std::ostream os(&sb);
os.setstate(std::ios_base::eofbit);
assert(&os.seekp(10) == &os);
assert(seekpos_called == 1);
assert(os.rdstate() == std::ios_base::eofbit);
}
}
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