Better way to say x == Foo::A || x == Foo::B || x == Foo::C || …?

Question

Let\'s say I have a bunch of well-known values, like this (but const char * is just an example, it could be more complicated):

const char *A = \"A\"         


        

Answer 1

Expressions of the type

if (some_complicated_expression_with_ugly_return_type == A ||
    some_complicated_expression_with_ugly_return_type == C ||
    some_complicated_expression_with_ugly_return_type == E ||
    some_complicated_expression_with_ugly_return_type == G)
{
    ...
}

are quite common in code (well, a pre-computed expression is anyway). I think the best you can do for readability is pre-compute the expression and keep it as is.

ugly_return_type x = some_complicated_expression_with_ugly_return_type;
if (x == A ||
    x == C ||
    x == E ||
    x == G)
{
    ...
}

Developers are used to this type of syntax. This makes it a whole lot easier to understand when someone else is reading your code

It also expresses what you want perfectly. There's a reason this type of syntax is so widely used in existing code - because other alternatives are worse for readability.

Of course, you could wrap the condition in a function, but only if it's reusable and it logically makes sense (besides the point IMO).