// WARNING: DO NOT USE THESE SEQUENCES IN YOUR CODES. THEY ARE PRE-STANDARD LEGACIES. // IMPORTANT: trigraphs are disable by default. // Digraph sequences // // %:%: ## (preprocessor concatenation) // %: # // <% { // %> } // <: [ // :> ] // Trigraph sequences // // ??= # // ??< { // ??> } // ??( [ // ??) ] // ??/ \ // ??' ^ // ??! | // ??- ~ // Note: If a digraph sequence occures inside another token, for example, a quoted string, or a character constant, it will not be replaced. %:include %:define SIZE 9 int main() <% const char *digraph<:SIZE:> = <% "%:%:", "%: ", "<% ", "%> ", "<: ", ":> " %>; const char *diEqu<:SIZE:> = <% "##", "#", "{", "}", "[", "]" %>; const char *trigraph<:SIZE:> = <% "?\?=", "?\?<", "?\?>", "?\?(", "?\?)", "?\?/", "?\?'", "?\?!", "?\?-" %>; const char *triEqu<:SIZE:> = <% "#", "{", "}", "[", "]", "\\", "^", "|", "~" %>; printf("*** Digraph and Trigraph sequences ***\n\n"); printf("Trigraph | Equ | Digraph | Equ\n"); for (int i = 0; i < 30; ++i) printf("~"); printf("\n"); for (int i = 0; i < SIZE; ++i) printf("%s%6c| %s%3c| %s%4c| %s\n", trigraph<:i:>, ' ', triEqu<:i:>, ' ', digraph<:i:> == NULL ? " " : digraph<:i:>, ' ', diEqu<:i:> == NULL ? "" : diEqu<:i:>); %>

Digraph && Trigraph Sequences