How to require all elements of a parameter pack to satisfy a concept?

[JUANDENT]

See this code:

template<typename...T> requires is_arithmetic_v<T>...
int sum_by_fold(T...v)
{
	return (v + ... + 0);	// add all elements of v starting with 0
}

int x = sum_by_fold(1, 2.4, 78, 'a');

How can I ensure every parameter in the pack is arithmetic?

Thank you in advance

[mbozzi]

Use a fold expression:
requires (is_arithmetic_v<T> && ...)

[JUANDENT]

thanks!!!