//--------- ABCD|DEFGH|EFGHI|A{4,}
egrep 0m50.036s
CTRE 0m3.982s
PCRE 0m8.621s
std::regex 0m55.058s
//--------- [0-9a-fA-F]{8,16}
egrep 0m32.361s
CTRE 0m4.291s
PCRE 0m13.958s
std::regex 0m18.179s
//--------- ^([0-9]{4,16})?[aA]
egrep 0m12.819s
CTRE 0m2.844s
PCRE 0m2.614s
std::regex 0m22.876s
//--------- ([aAbB]{4,}|[xXyY]{4,}|[1234]{4,})0
egrep 1m45.696s
CTRE 0m7.623s
PCRE 0m39.808s
std::regex 1m2.799s