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rand/xoshiro: simplify state initialisation from seed_seq

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This commit is contained in:
Danny Robson 2020-11-12 11:07:14 +10:00
parent 7185af7961
commit 82d3c36ebd
1 changed files with 5 additions and 12 deletions
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17
rand/xoshiro.cpp
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@ -39,18 +39,11 @@ xoshiro256plusplus::xoshiro256plusplus (u64 _seed)
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
xoshiro256plusplus::xoshiro256plusplus (std::seed_seq &seq) xoshiro256plusplus::xoshiro256plusplus (std::seed_seq &seq)
{ {
std::generate ( u32 parts[8];
std::begin (m_state), seq.generate (std::begin (parts), std::end (parts));
std::end (m_state),
[&] (void) { for (int i = 0; i < std::ssize (m_state); ++i)
u64 parts[2]; m_state[i] = u64 (parts[i * 2]) << 32 | parts[i * 2 + 1];
seq.generate (
std::begin (parts),
std::end (parts)
);
return parts[0] << 4 | parts[1];
}
);
} }