Function builtin_identical 

fn builtin_identical(
    args: &[RValue],
    _: &[(String, RValue)],
) -> Result<RValue, RError>

Test if two objects are exactly identical.

Performs deep structural comparison: type, length, element values, and attributes must all match. NaN == NaN is TRUE (unlike ==). NA == NA is TRUE. Lists are compared recursively.

@param x first object @param y second object @return logical scalar