Merge #13480: Avoid copies in range-for loops and add a warning to detect them

d92204c900d55ebaf2af5c900162b3c2c8c296e2 build: add warning to detect hidden copies in range-for loops (Cory Fields)
466e16e0e8523909f9968c5823691b1d4a3d8175 cleanup: avoid hidden copies in range-for loops (Cory Fields)

Pull request description:

  Following-up on #13241, which was itself a follow-up of #12169.

  See title. Fixing these would otherwise be a continuous process, adding the warning should keep them from cropping up.

  Note that the warning seems to be Clang-only for now.

Tree-SHA512: ccfb769c3128b3f92c95715abcf21ee2496fe2aa384f80efead1529a28eeb56b98995b531b49a089f8142601389e63f7bb935963d724eacde4f5e1b4a024934b

1 files changed, 2 insertions, 2 deletions

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 1c6dba0c9c..8090172e3f 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -69,12 +69,12 @@ void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap &cachedDescendan
         setAllDescendants.insert(cit);
         stageEntries.erase(cit);
         const setEntries &setChildren = GetMemPoolChildren(cit);
-        for (const txiter childEntry : setChildren) {
+        for (txiter childEntry : setChildren) {
             cacheMap::iterator cacheIt = cachedDescendants.find(childEntry);
             if (cacheIt != cachedDescendants.end()) {
                 // We've already calculated this one, just add the entries for this set
                 // but don't traverse again.
-                for (const txiter cacheEntry : cacheIt->second) {
+                for (txiter cacheEntry : cacheIt->second) {
                     setAllDescendants.insert(cacheEntry);
                 }
             } else if (!setAllDescendants.count(childEntry)) {