After #10193, approx. five instances of this warning are printed when compiling with -Wshadow:
In file included from txmempool.cpp:14:
./reverse_iterator.h:20:22: warning: declaration shadows a field of 'reverse_range<T>' [-Wshadow]
reverse_range(T &x) : x(x) {}
^
./reverse_iterator.h:17:8: note: previous declaration is here
T &x;
^
1 warning generated.