Help me sort out the meaning of “{}” as a constructor argument

Re:Help me sort out the meaning of “{}” as a constructor arg... by paulddraper on Tuesday November 22, 2016 @03:46PM (#13017495)

> Undefined behavior is not specified

> unspecified is stronger than undefined because it gives requirements.

I do not understand what you are saying.

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Re:Help me sort out the meaning of “{}” as a constructor arg... by kazinator on Tuesday November 22, 2016 @04:17PM (#13017742)

"unspecified behavior" in C++ is a formal term denoting a situation in which requirements are in fact given. There are multiple possible requirements, and the implementation chooses which apply, without having to document the choice. So in fact something is specified, just not entirely.

"undefined behavior" refers to situations in which no requirements apply at all. (Truly unspecified in the regular sense of the word.)

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Re:Help me sort out the meaning of “{}” as a constructor arg... by paulddraper on Tuesday November 22, 2016 @07:11PM (#13018844)

Thanks, I understand your usage now.

Unspecified means the implementation has some leeway.

Undefined means the implementation can do anything.

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Re:Help me sort out the meaning of “{}” as a constructor arg... by kazinator on Tuesday November 22, 2016 @07:37PM (#13018961)

Yes; as in "unspecified which choice".

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