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[std-proposals] Subsets of std::bitset<N>

From: Frederick Virchanza Gotham <cauldwell.thomas_at_[hidden]>
Date: Tue, 24 Jan 2023 20:41:05 +0000
The member function:


takes no arguments. I think there should be an overload which takes an
argument to indicate the index of the starting bit. For example I'm
currently writing code for a microcontroller and I need to keep track
of the status of 256 FPGA addresses, and so I have:

    std::bitset<256u> my_bitset;

It would be nice to be able get the 8 most significant bits as follows:


and perhaps also allow a negative number, such that the following
would be equivalent:


Any maybe even allow a range of bits:

    my_bitset.ullong(247, 255);

And if the range is known at compile time, we could have a 'subset'
method as follows:

template<size_t N>
class bitset {
    template<size_t a, size_t z>
    bitset<z + 1u - a> subset(void);

int main(void)
    bitset<256u> my_bitset;

    bitset<8u> my_subset = my_bitset.subset<248u,255u>();

Received on 2023-01-24 20:41:17