Define macro helper

src/macro_utils.jl

@@ -5,8 +5,6 @@ function materialize_args(expr::Expr)
     return (expr.args[2], expr.args[3])
 end
 
-function fused(expr) end
-
 macro fused(expr)
     _pairs = gensym()
     quote
@@ -41,15 +39,50 @@ end
 
 fused_pairs(expr::Expr) = Meta.parse(_fused_pairs(expr))
 
-macro fused_multibroadcast(expr)
-    esc(fused_multibroadcast("MultiBroadcastFusion.FusedMultiBroadcast", expr))
+"""
+    @make_fused type_name fused_named
+
+This macro
+ - Imports MultiBroadcastFusion
+ - Defines a type, `type_name`
+ - Defines a macro, `@fused_name`
+
+This allows users to flexibility
+to customize their broadcast fusion.
+
+# Example
+```julia
+import MultiBroadcastFusion as MBF
+MBF.@make_fused MyFusedBroadcast my_fused
+
+Base.copyto!(fmb::MyFusedBroadcast) = println("You're ready to fuse!")
+
+x1 = rand(3,3)
+y1 = rand(3,3)
+y2 = rand(3,3)
+
+# 4 reads, 2 writes
+@my_fused begin
+  @. y1 = x1
+  @. y2 = x1
 end
+```
+"""
+macro make_fused(type_name, fused_name)
+    macrodef = quote
+        import MultiBroadcastFusion
+        macro $fused_name(expr)
+            Base.copyto!($type_name(MultiBroadcastFusion.fused_pairs(expr)))
+        end
+    end
 
-macro fused_multibroadcast(fmb, expr)
-    esc(fused_multibroadcast(fmb, expr))
+    esc(quote
+        struct $type_name{T}
+            pairs::T
+        end
+        $macrodef
+    end)
 end
-fused_multibroadcast(fmb, expr::Expr) =
-    Meta.parse("$(fmb)($(_fused_pairs(expr)))")
 
 function build_expr(s::String, code_remain)
     n_subs = count("%", s)

test/expr_fused_pairs.jl

@@ -15,16 +15,3 @@ import MultiBroadcastFusion as MBF
     ))
     @test MBF.fused_pairs(expr_in) == expr_out
 end
-
-@testset "fused_multibroadcast" begin
-    expr_in = quote
-        @. y1 = x1 + x2 + x3 + x4
-        @. y2 = x2 + x3 + x4 + x5
-    end
-
-    expr_out = :(MultiBroadcastFusion.FusedMultiBroadcast((
-        Pair(y1, Base.broadcasted(+, x1, x2, x3, x4)),
-        Pair(y2, Base.broadcasted(+, x2, x3, x4, x5)),
-    )))
-    @test MBF.fused_multibroadcast(MBF.FusedMultiBroadcast, expr_in) == expr_out
-end