Annex C (informative) Compatibility [diff]

C.6 C standard library [diff.library]

C.6.3 Modifications to definitions [diff.mods.to.definitions]

C.6.3.7 Macro NULL [diff.null]

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The macro NULL, defined in any of <clocale>, <cstddef>, <cstdio>, <cstdlib>, <cstring>, <ctime>, or <cwchar>, is an implementation-defined null pointer constant in C++ ([support.types]).