哪些C＃编译器错误没有记录？

Question

This is meant to be a collection of possible C# compiler errors that are not documented.

If you encounter such an error, please post an answer here listing:

• The error number (CS nnnn )
• The associated error message
• If possible, a small snippet of code that will produce the error

Example:

CS0224:

A method with vararg cannot be generic, be in a generic type, or have a params parameter

Produced by:

 int Foo<T>(__arglist) { return 0; } 

If someone has already posted an answer listing the error you encountered, then edit that answer to add additional details.

The list of documented errors can be found on MSDN . There seem to be quite a few missing...

Answer 1

Found in the compiler string resource table but not in the MSDN Library index. Many of them are surely obsolete, some smell like interesting undocumented features like support for modules and testing. Checked up to CS2000:

CS0018: Operator 'xxx' not yet implemented
CS0240: 'xxx' cannot be both abstract and sealed (now CS0418)
CS0679: Other languages may permit the internal virtual member 'xxx' to be overridden
CS0767: Cannot inherit interface 'xxx' with the specified type parameters because it causes method 'yyy' to contain overloads which differ only on ref and out
CS0846: An expression tree may not contain a call or invocation that uses optional arguments
CS0847: An expression tree may not contain an indexed property
CS0848: Indexed property 'xxx' has non-optional arguments which must be provided
CS0849: Indexed property 'xxx' must have all arguments optional
CS0850: Partial declarations of 'xxx' must have the same type parameter names and variance modifiers in the same order
CS0851: Using 'is' to test compatibility with 'dynamic' is essentially identical to testing compatibility with 'object' and will succeed for all non-null values
CS1114: Member 'yyy' on embedded interop type 'xxx' cannot be evaluated while debugging since it is never referenced in the program. Consider casting the source object to type 'dynamic' first or building with the 'Embed Interop Types' property set to false when debugging
CS1543: Added module 'xxx' has unresolved reference to type 'yyy'
CS1544: Added module 'yyy' references module 'xxx' which was not added
CS1595: Delegate 'xxx' has some invalid arguments
CS1735: Ignoring /win32manifest for module because it only applies to assemblies
CS1736: Cannot convert 'xxx' to delegate because some of the return types in the block are not implicitly convertible to the delegate return type
CS1737: Expected parameter
CS1738: Named argument specifications must appear after all fixed arguments have been specified. Please use language version 7.2 or greater to allow non-trailing main arguments.
CS1739: Filename given with /appconfig is too long or invalid. Re-purposed in Roslyn (C# v6) to: The best overload for 'M' does not have a parameter named 'x'.
CS1903: Unrecognized value 'xxx' provided for '/test' option
CS1904: 'xxx' is not a valid warning number

Answer 2

CS0002:

Unable to load message string from resources

Produced by:

Most likely due to damage to the string table resource or a completely missing cscui.dll so it can't display any error messages. Reference question is here .

Answer 3

CS1669:

__arglist is not valid in this context

Produced by:

delegate int Bar(__arglist);

Answer 4

More like Leppie's example, found in the compiler string resource table and presumably triggered by undocumented keywords:

CS0190: The __arglist construct is valid only within a variable argument method
CS0224: A method with vararg cannot be generic, be in a generic type, or have a parameter array
CS0257: An __arglist parameter must be the last parameter in a formal parameter list

Answer 5

CS1738:

Named argument specifications must appear after all fixed arguments have been specified. Please use language version 7.2 or greater to allow non-trailing main arguments.

Produced by

string str = GetNewString(isAllowed: isUserAllowed, str);

Potential Solution: Upgrade to C# version 7.2 or greater

Right-click on the project to upgrade --> Properties --> Build --> Advanced --> Language version.