integer literal in C++

In C++, integer literal can be decimal-literal, octal-literal, hex-literal, or binary-literal;
Integer literal can have integer-suffix: unsigned-suffix (u or U), long-suffix (l or L), long-long-suffix (ll or LL), size-suffix (z or Z)
Optional single quotes (') may be inserted between the digits as a separator. They are ignored by the compiler.