Testing range-based for loop over explicitly created std::initializer_list

gistfile1.txt

Results of a few quick tests performed in response to:
https://twitter.com/Steven_Pigeon/status/1121900020746338305


// This is the original version that HAS the bug (garbage value encountered during iteration):
for (const AxisRay& faceRelVedge : std::initializer_list<AxisRay>{
    {{0, 0, -1}, Axis3::YNeg},
    {{0, 1, 0}, Axis3::ZPos},
    {{-2, -1, 0}, Axis3::ZPos},
    {{-1, -1, -1}, Axis3::XPos}}) {
    Topology::UsedVoxelFaceTraits::Key faceKey = {nextVedgeToWorld * (faceRelVedge.pos * (QStep / 2)), nextVedgeToWorld.rot * faceRelVedge.dir};
    auto faceCursor = topo.usedVoxelFaces.findOrInsert(faceKey);
    TURF_ASSERT(!faceCursor.wasFound());
}


// This version DOES NOT HAVE the bug:
std::initializer_list<AxisRay> tempList{
    {{0, 0, -1}, Axis3::YNeg},
    {{0, 1, 0}, Axis3::ZPos},
    {{-2, -1, 0}, Axis3::ZPos},
    {{-1, -1, -1}, Axis3::XPos}};
for (const AxisRay& faceRelVedge : tempList) {
    Topology::UsedVoxelFaceTraits::Key faceKey = {nextVedgeToWorld * (faceRelVedge.pos * (QStep / 2)), nextVedgeToWorld.rot * faceRelVedge.dir};
    auto faceCursor = topo.usedVoxelFaces.findOrInsert(faceKey);
    TURF_ASSERT(!faceCursor.wasFound());
}


// This version DOES NOT HAVE the bug:
auto tempList = std::initializer_list<AxisRay>{
    {{0, 0, -1}, Axis3::YNeg},
    {{0, 1, 0}, Axis3::ZPos},
    {{-2, -1, 0}, Axis3::ZPos},
    {{-1, -1, -1}, Axis3::XPos}};
for (const AxisRay& faceRelVedge : tempList) {
    Topology::UsedVoxelFaceTraits::Key faceKey = {nextVedgeToWorld * (faceRelVedge.pos * (QStep / 2)), nextVedgeToWorld.rot * faceRelVedge.dir};
    auto faceCursor = topo.usedVoxelFaces.findOrInsert(faceKey);
    TURF_ASSERT(!faceCursor.wasFound());
}


// This version HAS the bug (garbage value again encountered during iteration):
auto&& tempList = std::initializer_list<AxisRay>{
    {{0, 0, -1}, Axis3::YNeg},
    {{0, 1, 0}, Axis3::ZPos},
    {{-2, -1, 0}, Axis3::ZPos},
    {{-1, -1, -1}, Axis3::XPos}};
for (const AxisRay& faceRelVedge : tempList) {
    Topology::UsedVoxelFaceTraits::Key faceKey = {nextVedgeToWorld * (faceRelVedge.pos * (QStep / 2)), nextVedgeToWorld.rot * faceRelVedge.dir};
    auto faceCursor = topo.usedVoxelFaces.findOrInsert(faceKey);
    TURF_ASSERT(!faceCursor.wasFound());
}                                                                


// This version HAS the bug (garbage value again encountered during iteration):
const auto& tempList = std::initializer_list<AxisRay>{
    {{0, 0, -1}, Axis3::YNeg},
    {{0, 1, 0}, Axis3::ZPos},
    {{-2, -1, 0}, Axis3::ZPos},
    {{-1, -1, -1}, Axis3::XPos}};
for (const AxisRay& faceRelVedge : tempList) {
    Topology::UsedVoxelFaceTraits::Key faceKey = {nextVedgeToWorld * (faceRelVedge.pos * (QStep / 2)), nextVedgeToWorld.rot * faceRelVedge.dir};
    auto faceCursor = topo.usedVoxelFaces.findOrInsert(faceKey);
    TURF_ASSERT(!faceCursor.wasFound());
}