Add support for nonnull constraints #830
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BillWagner
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Rebased on latest draft-v8 on 09/25/2023 |
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@BillWagner On yesterday’s TG2 call, you wondered if you had resolved this PR as part of your other nullable-related work, and I offered to take a look. Looking at the Files changed and the current version of classes.md, I see the following:
So the remaining question is, "Did we decide to reject Item 3, or do we still need to look at that?" I'm guessing the latter. |
See #1246 |
| @@ -490,7 +491,49 @@ Any constraints shall be consistent among dependent type parameters. If type par | |||
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| It is valid for `S` to have the value type constraint and `T` to have the reference type constraint. Effectively this limits `T` to the types `System.Object`, `System.ValueType`, `System.Enum`, and any interface type. | |||
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| If the `where` clause for a type parameter includes a constructor constraint (which has the form `new()`), it is possible to use the `new` operator to create instances of the type ([§12.8.17.2](expressions.md#128172-object-creation-expressions)). Any type argument used for a type parameter with a constructor constraint shall be a value type, a non-abstract class having a public parameterless constructor, or a type parameter having the value type constraint or constructor constraint. | |||
| The token `notnull` is neither a keyword nor a contextual keyword. When it is encountered, it will either: | |||
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As per #1246, we believe it is a contextual keyword.
| If the `where` clause for a type parameter includes a constructor constraint (which has the form `new()`), it is possible to use the `new` operator to create instances of the type ([§12.8.17.2](expressions.md#128172-object-creation-expressions)). Any type argument used for a type parameter with a constructor constraint shall be a value type, a non-abstract class having a public parameterless constructor, or a type parameter having the value type constraint or constructor constraint. | ||
| The token `notnull` is neither a keyword nor a contextual keyword. When it is encountered, it will either: | ||
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| - Bind to a type named `notnull` |
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@gafter pointed out it could be an alias - we can just strike "named notnull", or see @Nigel-Ecma's wording in #1246.
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Closing as #1256 involves creating a replacement for this. |
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@RexJaeschke - please don't delete the branch for this PR, as I'll want to copy from it... |
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