From cppreference.com
intthrd_equal(thrd_tlhs,thrd_trhs);(since C11)Checks whether lhs and rhs refer to the same thread.
Parameters
lhs, rhs - threads to compare Return value
Non-zero value if lhs and rhs refer to the same value, 0 otherwise.
References
C17 standard (ISO/IEC 9899:2018):
7.26.5.4 The thrd_equal function (p: 280)
C11 standard (ISO/IEC 9899:2011):
7.26.5.4 The thrd_equal function (p: 384)
See also