Two consecutive question marks signify the start of a trigraph sequence. According to the C Standard, section subclause 5.2.1.1 [ISO/IEC 9899:2011],
...
Bibliography
[ISO/IEC 9899:2011] | Section Subclause 5.2.1.1, "Trigraph Sequences" |
...
Two consecutive question marks signify the start of a trigraph sequence. According to the C Standard, section subclause 5.2.1.1 [ISO/IEC 9899:2011],
...
[ISO/IEC 9899:2011] | Section Subclause 5.2.1.1, "Trigraph Sequences" |
...