16 Library introduction [library]

16.3 Definitions [definitions]

16.3.26[defns.required.behavior]required behavior

description of replacement function and handler function semantics applicable to both the behavior provided by the implementation and the behavior of any such function definition in the program
[Note
:
If such a function defined in a C++ program fails to meet the required behavior when it executes, the behavior is undefined.
— end note
]