why std::vector that is never resized?

[xBZZZZ]

if I replace

mold/src/icf.cc

Line 518 in 2a78b1b

std::vector<std::vector<Digest>> digests(3);

with

std::array<std::vector<Digest>,3> digests;

mold compiles

why std::vector used in original code?

[rui314]

Or you could write it as std::vector<Digest> digests[3]. But that tiny difference doesn't matter, as all of them work fine.