#include <strstream>
#include <cassert>
int main()
{
{
char buf[] = "0123456789";
std::strstreambuf sb(buf, 0);
assert(sb.pubseekpos(3, std::ios_base::out) == -1);
assert(sb.pubseekpos(3, std::ios_base::in | std::ios_base::out) == -1);
assert(sb.pubseekpos(3, std::ios_base::in) == 3);
assert(sb.sgetc() == '3');
}
{
char buf[] = "0123456789";
std::strstreambuf sb(buf, 0, buf);
assert(sb.pubseekpos(3, std::ios_base::in) == 3);
assert(sb.pubseekpos(3, std::ios_base::out | std::ios_base::in) == 3);
assert(sb.pubseekpos(3, std::ios_base::out) == 3);
assert(sb.sputc('a') == 'a');
assert(sb.str() == std::string("012a456789"));
}
}