Allow Func<int, string> = static i => i.ToString();.

• Proposal added (here)
• Discussed in LDM 2019-10-21
• Decision in LDM
• Finalized (done, rejected, inactive)
• Spec'ed

To avoid accidentally capturing any local state when supplying lambda functions for method arguments, prefix the lambda declaration with the static keyword. This makes the lambda function just like a static method, no capturing locals and no access to this or base.

int y = 10;
someMethod(x => x + y); // captures 'y', causing unintended allocation.

with this proposal you could the static keyword to make this an error.

int y = 10;
someMethod(static x => x + y); // error!

const int y = 10;
someMethod(static x => x + y); // okay :-)

LDM history:

• 10/21/2019