What is the rationale in allowing `?` to be escaped?
c++, language-design, language-lawyer
Solution
`\"` gives consistency between single-quoted character literals and double-quoted string literals (they're defined to use the same escape sequences, as a result `\'` and `\"` can be used in both). I'm slightly guessing, but I reckon the committee just figured it was too much bother to define different escape sequences in each, for no benefit and arguably a slight detriment.
`\?` is for avoiding trigraphs: `??=` is a trigraph, `?\?=` isn't.
Problem
From 2.13.2/3 The double quote `"` and the question mark `?`, can be represented as themselves or by the escape sequences `\"` and `\?` [...]. Simply put, the following: ``` char x = '\?'; //or '\"' char y = '?'; //or '"' ``` represent the same character. Why treat these two (especially `?`) differently than other characters?