https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62036
Bug ID: 62036
Summary: Braced-init-list issuing -Wsequence-point warning
Product: gcc
Version: 4.8.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dacamara.cameron at gmail dot com
#include <algorithm>
#include <iostream>
#include <iterator>
#include <thread>
int main() {
int arr[10];
std::iota(std::begin(arr), std::end(arr), 1);
using itr_t = decltype(std::begin(arr));
// the function that will display each element
auto f = [] (itr_t first, itr_t last) {while (first != last)
std::cout<<*(first++)<<' ';};
// we have 3 threads so we need to figure out the ranges for each thread to
show
int increment = std::distance(std::begin(arr), std::end(arr)) / 3;
auto first = std::begin(arr);
auto to = first + increment;
auto last = std::end(arr);
std::thread threads[3] = {
std::thread{f, first, to},
std::thread{f, (first = to), (to += increment)},
std::thread{f, (first = to), last} // go to last here to account for
odd array sizes
};
for (auto&& t : threads) t.join();
}
I'm getting the sequence point warning with this piece of code and when I
execute it the thread at threads[1] prints nothing whatsoever. This should be
well defined according to the standard (I'm using sec. 8.5.4.4 as reference).
The fact that gcc even issues the -Wsequence-point warning is indicative that
the standard isn't being followed.
