lua_shared

Function Loptlstring

Source 
pub unsafe extern "C" fn Loptlstring(
    state: lua_State,
    index: i32,
    default: *const u8,
    length: &mut usize,
) -> *const u8
Expand description

If the function argument index is a string, returns this string. If this argument is absent or is nil, returns default. Otherwise, raises an error.

If length is not NULL, fills the position *length with the results’s length.