SRELL (std::regex-like library) is a Unicode-aware regular expression template
library for C++.

* Header-only and the same class design as std::regex

SRELL is a header-only template library and does not need any
installation. SRELL has an ECMAScript (JavaScript) compatible regular expression
engine wrapped into the same class design as std::regex. As APIs are compatible,
SRELL can be used in the same way as std::regex (or boost::regex on which
std::regex is based).

* Unicode-specific implementation

SRELL has native support for Unicode.

* Consideration for ignore-case (icase) search

SRELL has been tuned up not to slow down remarkably when case-insensitive
(icase) search is performed.
