As spotted by user Blinken: https://bitcointalk.org/index.php?topic=1828929.msg18205985#msg18205985
In the bitcoin core file key.h there is a typo:
//! Check whether the 32-byte array pointed to be vch is valid keydata.
bool static Check(const unsigned char* vch);
The comment should read:
//! Check whether the 32-byte array pointed to by vch is valid keydata.
