Add some macros from Gaius.jl

src/Augustus.jl

@@ -1,3 +1,6 @@
 module Augustus
 
+include("types.jl")
+include("macros.jl")
+
 end # module Augustus

src/macros.jl

@@ -0,0 +1,20 @@
+# Some of the code in this file is taken from Gaius.jl (license: MIT)
+# https://github.com/MasonProtter/Gaius.jl
+
+# Note this does not support changing the number of threads at runtime
+
+macro _spawn(ex)
+    if Threads.nthreads() > 1
+        esc(Expr(:macrocall, Expr(:(.), :Threads, QuoteNode(Symbol("@spawn"))), __source__, ex))
+    else
+        esc(ex)
+    end
+end
+
+macro _sync(ex)
+    if Threads.nthreads() > 1
+        esc(Expr(:macrocall, Symbol("@sync"), __source__, ex))
+    else
+        esc(ex)
+    end
+end

test/macros.jl

@@ -0,0 +1,12 @@
+@testset "Macros" begin
+    a = Augustus.@_sync begin
+        Augustus.@_spawn begin
+            1 + 1
+        end
+    end
+    if Threads.nthreads() > 1
+        @test fetch(a) == 2
+    else
+        @test a == 2
+    end
+end

test/runtests.jl

@@ -11,5 +11,4 @@ versioninfo()
 
 @info("Running tests with $(Threads.nthreads()) threads")
 
-@testset "Augustus.jl" begin
-end
+include("macros.jl")