https://cppinsights.io/s/5ced24b2

So, this code
template<class...Match>
bool search(char ch, Match&&...matchers) {
return (matchers(ch) || ...);
}
search('A', ::isalpha, ::isdigit, { lambda });

gets insighted into
bool search<... params...>(char ch, int (&matchers)(int) noexcept, int (&matchers)(int) noexcept, __lambda_12_50 && __matchers3)

Notice how first and second parameters are named 'matchers', but the third parameter is named 'matchers3'. It looks like there is an internal counter, it is just being output for lambda and not for regular function argument.