Trying to build kdevelop-pg-qt with Qt 5.14 results in an error:
.../kdev-pg/kdev-pg-regexp.cpp:44:23: error: redefinition of ‘struct std::hash<QBitArray>’
template<> struct hash< type > \
^~~~~~~~~~~~
.../kdev-pg/kdev-pg-regexp.cpp:53:1: note: in expansion of macro ‘q_Hash_to_tr1_hash’
q_Hash_to_tr1_hash(QBitArray)
^~~~~~~~~~~~~~~~~~
In file included from .../prefix514/include/QtCore/qvector.h:47:0,
from .../prefix514/include/QtCore/QVector:1,
from .../kdevelop-pg-qt/include/kdev-pg-char-sets.h:36,
from .../kdevelop-pg-qt/kdev-pg/kdev-pg-regexp.cpp:20:
.../prefix514/include/QtCore/qhashfunctions.h:209:1: note: previous definition of ‘struct std::hash<QBitArray>’
QT_SPECIALIZE_STD_HASH_TO_CALL_QHASH_BY_CREF(QBitArray)
^std::hash<QBitArray> is already specialized in Qt 5.14, so avoid redefinition with conditional compilation