Issue
I'm compiling the C++ code below with g++ 14.0.0:
g++ -I/path/to/c++/14.0.0 -L/path/to/c++/libstdc++ -ltbb -std=c++23 -o main main.cc
#include <iostream>
#include <algorithm>
#include <execution>
#include <ranges>
#include <thread>
#include <syncstream>
int main()
{
using namespace std::chrono_literals;
auto r = std::views::iota(0) | std::views::take(10);
auto input_range = std::ranges::common_view(r);
std::for_each(std::execution::par_unseq, std::ranges::begin(input_range), std::ranges::end(input_range),
[&](int i) {
std::thread::id this_id = std::this_thread::get_id();
std::this_thread::sleep_for(2000ms);
std::osyncstream(std::cout) << this_id << std::endl ;
});
return 0;
}
the code compiles but I get the warning
In function ‘_RandomAccessIterator __pstl::__internal::__brick_unique(_RandomAccessIterator, _RandomAccessIterator, _BinaryPredicate, std::true_type)’:
note: ‘#pragma message: [Parallel STL message]: "Vectorized algorithm unimplemented, redirected to serial"’
1219 | _PSTL_PRAGMA_MESSAGE("Vectorized algorithm unimplemented, redirected to serial");
I'm configuring gcc with
./configure --prefix=/path/to/install/dir --disable-multilib --with-system-zlib --enable-default-pie --enable-default-ssp --disable-fixincludes --with-mpfr=/path/to/mpfr --with-mpc=/path/to/mpc --with-gmp=/path/to/gmp --enable-languages=c,c++,fortran,go,lto,m2,objc,obj-c++ --no-create --no-recursion
and config.log has the variable PKG_CONFIG_PATH with the correct path to MKL TBB.
I thought that p2408 was implemented as per the this post.
Anyone knows what could I be doing wrong? TBB is installed
The code seems to have the same problem on godbolt.
Solution
Per the compiler support guide on cppreference only MSVC version 19.34 and above supports p2408R5.
Answered By - NathanOliver Answer Checked By - David Marino (WPSolving Volunteer)