Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Function is_digit

boost::algorithm::is_digit — is_digit predicate

unspecified is_digit(const std::locale & Loc = std::locale());

Construct the is_classified predicate for the ctype_base::digit category.

Parameters:

Loc

A locale used for classification

Returns:

An instance of the is_classified predicate