Boost multiprecision as array index
Hi to all, I unsuccessfully tried to use a boost multiprecision variable (object?) as index of an array. Int myArray[100]; uint128_t index = 23; int value = myArray[index]; This code don’t work. There is a way for to use a multiprecision as index of an array? Thanks. Claudio La Rosa
On 03/08/2021 07:34, Claudio La Rosa via Boost-users wrote:
Hi to all,
I unsuccessfully tried to use a boost multiprecision variable (object?) as index of an array.
Int myArray[100];
uint128_t index = 23;
int value = myArray[index];
This code don’t work.
There is a way for to use a multiprecision as index of an array?
You would need to explicitly cast the variable to a std::size_t. But I would rather question the wisdom of using a multiprecision type in that context? John. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
My array have only 3 elements, but I indexed it with an modulo operation (%) that use a uint128_t value. The result of modulo operation is a uint128_t value type. But well, I now use with success a standard cast for obtain a valid index type value! Thanks! Da: John Maddock via Boost-users Inviato: martedì 3 agosto 2021 18:40 A: Claudio La Rosa via Boost-users Cc: John Maddock Oggetto: Re: [Boost-users] Boost multiprecision as array index On 03/08/2021 07:34, Claudio La Rosa via Boost-users wrote:
Hi to all,
I unsuccessfully tried to use a boost multiprecision variable (object?) as index of an array.
Int myArray[100];
uint128_t index = 23;
int value = myArray[index];
This code don’t work.
There is a way for to use a multiprecision as index of an array?
You would need to explicitly cast the variable to a std::size_t. But I would rather question the wisdom of using a multiprecision type in that context? John. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org https://lists.boost.org/mailman/listinfo.cgi/boost-users
On 03/08/2021 17:53, Claudio La Rosa via Boost-users wrote:
My array have only 3 elements, but I indexed it with an modulo operation (%) that use a uint128_t value. The result of modulo operation is a uint128_t value type.
But well, I now use with success a standard cast for obtain a valid index type value!
OK, there is also a function integer_modulus(a,b) which returns the result of a%b as the type of b (since the result must be smaller than b). -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
participants (2)
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Claudio La Rosa -
John Maddock