Missing Mandates for the standard library

• Introduction
• Wording

Introduction

As the "Mandating the standard library" papers have progressed/been applied, a few bits have been missed; mostly because parts of the library have moved.

This paper fixes those bits.

Thanks to Richard Smith for enumerating these parts.

Thanks to Tim Song for his review of R0.

Changes from R0:

• Removed the changes from [res.on.required]
• Fix a mis-edit in [coroutine.handle.observers]
• Add edits for [coroutine.handle.resumption]
• Add a missing edit for [util.smartptr.atomic.weak]/3

Wording

These changes are based on N4842.

In [tab:cpp17.allocator], change the "Requires" to an "Preconditions":

Preconditions:Requires: (*p).m is well-defined.

Preconditions:Requires: (*q).m is well-defined.

Preconditions:Requires: p isshall be a value returned by an earlier call to allocate that has not been invalidated by an intervening call to deallocate. n matchesshall match the value passed to allocate to obtain this memory.

In [coroutine.handle.con]/2, change the "Requires" to an "Preconditions":

Preconditions:Requires: p is a reference to a promise object of a coroutine.

In [coroutine.handle.export.import]/2, change the "Requires" to an "Preconditions":

Preconditions:Requires: addr was obtained via a prior call to address

In [coroutine.handle.observers]/2, change the "Requires" to an "Preconditions":

Preconditions:Requires: *this refers to a suspended coroutine

In [coroutine.handle.resumption], edit /2, /3 /4, as follows:

Preconditions:Requires: *this refers to a suspended coroutine. The coroutine is not suspended at its final suspend point.

Effects: Resumes the execution of the coroutine. If the coroutine was suspended at its final suspend point, behavior is undefined.