Chained withers / with-expression possible

[msedi]

I have a read-only structure where properties are dependent from other properties in the same structure. It would be completely sufficient to have everything set in the initialization using a compound initialization with init it is not possible for several reasons, because in the example order might play a role, so I cannot access the Blocksize within the initialization:

 var gridSize1 = new CudaGridBlockSize
            {
                BlocksizeX = 64,
                BlocksizeY = 1,
                BlocksizeZ = 1,
                GridsizeX = ((width - 1) / BlocksizeX / 4) + 1,
                GridsizeY = ((height - 1) / BlocksizeY) + 1,
                GridsizeZ = ((depth - 1) / BlocksizeZ) + 1
            } 

so I came up with the idea of using withers but found that also here I have no access to the original. Is this even possible?

 var gridSize1 = new CudaGridBlockSize
            {
                BlocksizeX = 64,
                BlocksizeY = 1,
                BlocksizeZ = 1
            } 
            with
            {
                // Accessing gridsize1 does not work
                GridsizeX = ((width - 1) / gridSize1.BlocksizeX / 4) + 1,
                GridsizeY = ((height - 1) / gridSize1.BlocksizeY) + 1,
                GridsizeZ = ((depth - 1) / gridSize1.BlocksizeZ) + 1
            };

[HaloFour]

You can't access gridSize1 until after it has been assigned, which in your expression isn't until after the with expression which is why it's not accessible there.

If you assign the variable first you can use with in this manner:

 var gridSize1 = new CudaGridBlockSize
            {
                BlocksizeX = 64,
                BlocksizeY = 1,
                BlocksizeZ = 1
            } ;
  gridSize1 = gridSize1 with
            {
                GridsizeX = ((width - 1) / gridSize1.BlocksizeX / 4) + 1,
                GridsizeY = ((height - 1) / gridSize1.BlocksizeY) + 1,
                GridsizeZ = ((depth - 1) / gridSize1.BlocksizeZ) + 1
            };

There is a separate issue where improvements to initializers/withers are being considered but I don't think it includes attempting to reference other properties like this: #5176

[msedi]

@HaloFour. Thanks for the answer. I thought so and thats how I do it now. I found this problem when refactoring code to use readonly-structs. Do you think I should attach some proposal to #5176.