underflow.pass.cpp [plain text]
#include <sstream>
#include <cassert>
template <class CharT>
struct testbuf
: public std::basic_stringbuf<CharT>
{
typedef std::basic_stringbuf<CharT> base;
explicit testbuf(const std::basic_string<CharT>& str)
: base(str) {}
typename base::int_type underflow() {return base::underflow();}
void pbump(int n) {base::pbump(n);}
};
int main()
{
{
testbuf<char> sb("123");
sb.pbump(3);
assert(sb.underflow() == '1');
assert(sb.underflow() == '1');
assert(sb.snextc() == '2');
assert(sb.underflow() == '2');
assert(sb.underflow() == '2');
assert(sb.snextc() == '3');
assert(sb.underflow() == '3');
assert(sb.underflow() == '3');
assert(sb.snextc() == std::char_traits<char>::eof());
assert(sb.underflow() == std::char_traits<char>::eof());
assert(sb.underflow() == std::char_traits<char>::eof());
sb.sputc('4');
assert(sb.underflow() == '4');
assert(sb.underflow() == '4');
}
{
testbuf<wchar_t> sb(L"123");
sb.pbump(3);
assert(sb.underflow() == L'1');
assert(sb.underflow() == L'1');
assert(sb.snextc() == L'2');
assert(sb.underflow() == L'2');
assert(sb.underflow() == L'2');
assert(sb.snextc() == L'3');
assert(sb.underflow() == L'3');
assert(sb.underflow() == L'3');
assert(sb.snextc() == std::char_traits<wchar_t>::eof());
assert(sb.underflow() == std::char_traits<wchar_t>::eof());
assert(sb.underflow() == std::char_traits<wchar_t>::eof());
sb.sputc(L'4');
assert(sb.underflow() == L'4');
assert(sb.underflow() == L'4');
}
}