Function is_meta_character

regex/regex-syntax/src/lib.rs:153–159

Returns true if the give character has significance in a regex. These are the only characters that are allowed to be escaped, with one exception: an ASCII space character may be escaped when extended mode (with the `x` flag) is enabld. In particular, `is_meta_character(' ')` returns `false`. Note that the set of characters for which this function returns `true` or `false` is fixed and won't chan

(c: char)

/// Note that the set of characters for which this function returns `true` or
/// `false` is fixed and won't change in a semver compatible release.
pub fn is_meta_character(c: char) -> bool {
    match c {
        '\\' | '.' | '+' | '*' | '?' | '(' | ')' | '|' |
        '[' | ']' | '{' | '}' | '^' | '$' | '#' | '&' | '-' | '~' => true,
        _ => false,
    }
}

/// Returns true if and only if the given character is a Unicode word
/// character.