Skip to content

Implement LWG-4014 LWG-3809 changes behavior of some existing std::subtract_with_carry_engine code #5132

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Stephan T. Lavavej (StephanTLavavej) merged 2 commits into from
Dec 5, 2024
Merged

Implement LWG-4014 LWG-3809 changes behavior of some existing std::subtract_with_carry_engine code #5132

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a983215
Implement LWG-4014
frederick-vs-ja Nov 25, 2024
51f3dc9
Update version citations.
StephanTLavavej Nov 26, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion stl/inc/random
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -827,7 +827,7 @@ public:

void seed(_Seed_t _Value = 0u, bool _Readcy = false) { // set initial values from specified seed value
linear_congruential_engine<uint_least32_t, 40014U, 0U, 2147483563U> _Lc{
static_cast<uint_least32_t>(_Value == 0U ? default_seed : _Value)};
_Value == 0U ? default_seed : static_cast<uint_least32_t>(_Value % 2147483563U)};
_Reset(_Lc, _Readcy);
}

Expand Down
4 changes: 2 additions & 2 deletions tests/std/tests/Dev11_0577418_random_seed_0/test.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,14 +24,14 @@ int main() {
// Also test VSO-214595 "subtract_with_carry_engine::seed should accept result_type"
subtract_with_carry_engine<unsigned long long, 64, 10, 24> ull_swc;
ull_swc.seed(0x12341234'00000000ULL);
assert(run_10k(ull_swc) == 0x1DD6C263'C41EEED0ULL); // value changed by LWG-3809
assert(run_10k(ull_swc) == 0x01316AEA'3646F686ULL); // libstdc++ 14.2 and libc++ 19.1 agree, Boost 1.86.0 disagrees

assert(minstd_rand0(0) == minstd_rand0()); // N4964 [rand.eng.lcong]/5
assert(mt19937(0) != mt19937()); // N4964 [rand.eng.mers]/6
assert(ranlux24_base(0) == ranlux24_base()); // N4964 [rand.eng.sub]/7

assert(run_10k(minstd_rand0(0)) == 1043618065UL); // QED
assert(run_10k(mt19937(0)) == 1543171712UL); // Boost 1.52.0 agrees
assert(run_10k(mt19937(0)) == 1543171712UL); // Boost 1.86.0 agrees
assert(run_10k(ranlux24_base(0)) == 7937952UL); // QED

// Also test LWG-3809 Is std::subtract_with_carry_engine<uint16_t> supposed to work?
Expand Down