CODEWITHSUNDEEP
c++gmp
user688518
user688518

Reputation: 461

Cast mpz_class to int

Using gmp, I declare:

mpz_class x = 0;

but now if I want to use x as an index of an array, like so:

textArray[x];

I get this error "error: no match for 'operator[]' in 'testArray[x]'"

So how do I get around this?

Upvotes: 2

Views: 4929

Answers (1)

Zeta
Zeta

Reputation: 105876

The usual operator[] takes a size_t. You need to convert your mpz_class instance in a compatible type:

textArray[x.get_ui()];

Note that this will lead to trouble if x is greater than std::numeric_limits<unsigned long>::max() (check with x.fits_ulong_p()). Note that mpz_class is also most-likely not very well suited for that task. Ask yourself: should an index be arbitrary large?

See also:

Upvotes: 11

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