--- a/src/LazyTensors/tuple_manipulation.jl	Tue Mar 22 09:53:26 2022 +0100
+++ b/src/LazyTensors/tuple_manipulation.jl	Tue Mar 22 10:42:19 2022 +0100
@@ -74,3 +74,23 @@
 flatten_tuple(t::NTuple{N, Number} where N) = t
 flatten_tuple(t::Tuple) = ((flatten_tuple.(t)...)...,) # simplify?
 flatten_tuple(ts::Vararg) = flatten_tuple(ts)
+
+
+function left_pad_tuple(t, val, N)
+    if N < length(t)
+        throw(DomainError(N, "Can't pad tuple of length $(length(t)) to $N elements"))
+    end
+
+    padding = ntuple(i->val, N-length(t))
+    return (padding..., t...)
+end
+
+function right_pad_tuple(t, val, N)
+    if N < length(t)
+        throw(DomainError(N, "Can't pad tuple of length $(length(t)) to $N elements"))
+    end
+
+    padding = ntuple(i->val, N-length(t))
+    return (t..., padding...)
+end
+

--- a/test/LazyTensors/tuple_manipulation_test.jl	Tue Mar 22 09:53:26 2022 +0100
+++ b/test/LazyTensors/tuple_manipulation_test.jl	Tue Mar 22 10:42:19 2022 +0100
@@ -60,3 +60,19 @@
     @test LazyTensors.flatten_tuple((1,2,(3,(4,5)),6)) == (1,2,3,4,5,6)
     @test LazyTensors.flatten_tuple(((1,2),(3,4),(5,),6)) == (1,2,3,4,5,6)
 end
+
+@testset "left_pad_tuple" begin
+    @test LazyTensors.left_pad_tuple((1,2), 0, 2) == (1,2)
+    @test LazyTensors.left_pad_tuple((1,2), 0, 3) == (0,1,2)
+    @test LazyTensors.left_pad_tuple((3,2), 1, 6) == (1,1,1,1,3,2)
+
+    @test_throws DomainError(0, "Can't pad tuple of length 2 to 0 elements") LazyTensors.left_pad_tuple((1,2), 0, 0) == (1,2)
+end
+
+@testset "right_pad_tuple" begin
+    @test LazyTensors.right_pad_tuple((1,2), 0, 2) == (1,2)
+    @test LazyTensors.right_pad_tuple((1,2), 0, 3) == (1,2,0)
+    @test LazyTensors.right_pad_tuple((3,2), 1, 6) == (3,2,1,1,1,1)
+
+    @test_throws DomainError(0, "Can't pad tuple of length 2 to 0 elements") LazyTensors.right_pad_tuple((1,2), 0, 0) == (1,2)
+end