Possessive qualifier "?+" is not supported.

[heyingge-1560733]

1. Possessive qualifier "?+" is not supported. ~2. ctre::range matches an empty string will cause infinite loop, e.g., for (auto&& m : ctre::range<"a|(ab)?">("aab"));~ (moved to issue #222)

[BenBE]

Isn't the first one supposed to be +??

[heyingge-1560733]

Why?

[Alcaro]

They're different things. +? is + but nongreedy (match as few times as possible while still making the overall regex match); ?+ is ? but possessive (match as many times as possible, and never backtrack; if backtracking would be needed, backtrack somewhere earlier in the regex, or just fail).

[hanickadot]

Splitting this issue into two: https://github.com/hanickadot/compile-time-regular-expressions/issues/222

[heyingge-1560733]

Sorry, I don't get it. I am saying that ?+ is not supported and it is a possessive qualifier, isn't it? CTRE returns syntax error while compiling, e.g., ?+.

[hanickadot]

@heyingge-1560733 the possessive optional added in 2e8aaf2aa09a651a05144da61b7e6c7606dd247c, I originally didn't implement it because I didn't see any usecase for it. But after recent unification of cycles and optionals it makes sense to have it.

[heyingge-1560733]

@hanickadot I will try later. Thanks!