how to set a large constant with bitwise operation on ULong?

Question

This work nicely

Public Const test As ULong = 1 << 30

This doesn't work nicely

Public Const test As ULong = 1 << 31

It create this error:

Constant expression not representable in type 'ULong'

Anyone know how to make it work?

This does work:

Public Const test As Long = 1 << 31

But I have to use ULong

Answer 1

Try the following:

Public Const test As ULong = 1UL << 31 

You need to explicitly tell the compiler you are doing the operation on a ULong.

The C# equivalent works:

public const ulong test  = 1UL << 31;

Answer 2

You cannot shift 1 << 31 with a Long datatype, so you get this error.

However, this is because 1, as an integer literal, is treated as an Int32, which is the default integer literal.

You should work around this by defining this as:

Public Const test As ULong = 1UL << 30
Public Const test2 As ULong = 1UL << 31

The UL flag says to make the 1 an unsigned long. See Type characters for details.