[streambuf.pub.pback]

🔗

int_type sputbackc(char_type c);

Effects: If the input sequence putback position is not available, or if traits::eq(c, gptr()[-1]) is false, returns pbackfail(traits::to_int_type(c)).

Otherwise, decrements the next pointer for the input sequence and returns traits::to_int_type(*gptr().

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int_type sungetc();

Effects: If the input sequence putback position is not available, returns pbackfail().

Otherwise, decrements the next pointer for the input sequence and returns traits::to_int_type(*gptr().

31 Input/output library [input.output]

31.6 Stream buffers [stream.buffers]

31.6.3 Class template basic_streambuf [streambuf]

31.6.3.3 Public member functions [streambuf.members]

31.6.3.3.4 Putback [streambuf.pub.pback]