var sz: array[64, byte] = [ 1,2,3,4] # add this init array method pls ...
# want 4 byte after all zero but I only have 30 byte val want set it.
# really dont like manual copy input var [1,2,3,4,0,0,0,0,0,0,0,0,0,0,0 ...]
# -------------
# ↓ I use this method in proj, looks like very cumbersome and unattractive
var ssz: array[64, byte] # ssz must 64byte, use ssz[0xF] will crash if haven't
var tssz = [1,2,3,4]
CopyMem(ssz, tssz, tssz.len)
# want easy init like this
var ssz[64, byte] = [1,2,3,4, ...0 ] after all 0, and [ 1,2,3,4, ...0xf] 4byte after all 0xf
It's not any more attractive but it removes the overhead of copying memory at runtime:
proc `[]=`*[T](arr: var openArray[T], slice: Slice[int], val: T) =
for x in slice:
arr[x] = val
proc `[]=`*[T](arr: var openArray[T], slice: HSlice[int, BackwardsIndex], val: T) =
for x in slice.a.. arr.len - int(slice.b):
arr[x] = val
proc `[]=`*[T](arr: var openArray[T], slice: HSlice[int, BackwardsIndex], val: openArray[T]) =
for x in slice.a.. arr.len - int(slice.b):
arr[x] = val[x - slice.a]
proc `[]=`*[T](arr: var openArray[T], slice: Slice[BackwardsIndex], val: openArray[T]) =
for x in arr.len - int(slice.a) .. arr.len - int(slice.b):
arr[x] = val[x - arr.len - int(slice.a)]
proc `[]=`*[T](arr: var openArray[T], slice: Slice[int], val: openArray[T]) =
for x in slice.a..slice.b:
arr[x] = val[x - slice.a]
var sz = static:
var val: array[64, byte]
val[0..3] = [1u8, 2, 3, 4]
val
echo sz
var ssz = static: # Do this at CT instead of runtime
var val: array[64, byte]
val[0..3] = [1u8, 2, 3, 4]
val[4..^1] = 0xf
val
echo ssz