//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <regex>

// template <class charT, class traits = regex_traits<charT>> class basic_regex;

// template <class ST, class SA>
//    basic_regex(const basic_string<charT, ST, SA>& s);

#include <regex>
#include <cassert>

static bool error_escape_thrown(const char *pat) 
{
    bool result = false;
    try {
        std::regex re(pat);
    } catch (std::regex_error &ex) {
        result = (ex.code() == std::regex_constants::error_escape);
    }
    return result;
}

int main() 
{
    assert(error_escape_thrown("[\\a]"));
    assert(error_escape_thrown("\\a"));

    assert(error_escape_thrown("[\\e]"));
    assert(error_escape_thrown("\\e"));

    assert(error_escape_thrown("[\\c:]"));
    assert(error_escape_thrown("\\c:"));
    assert(error_escape_thrown("\\c"));
    assert(!error_escape_thrown("[\\cA]"));
    assert(!error_escape_thrown("\\cA"));

}