Avoid iterating twice over generators when there is an exception (#137)

... at least in Julia >= 1.11 which fixed it via JuliaLang/julia#53151

src/ordered_dict.jl

@@ -67,15 +67,20 @@ OrderedDict(kv::AbstractDict{K,V}) where {K,V}         = OrderedDict{K,V}(kv)
 OrderedDict(ps::Pair{K,V}...) where {K,V} = OrderedDict{K,V}(ps)
 OrderedDict(ps::Pair...)                  = OrderedDict(ps)
 
-function OrderedDict(kv)
-    try
-        dict_with_eltype((K, V) -> OrderedDict{K, V}, kv, eltype(kv))
-    catch e
-        if isempty(methods(iterate, (typeof(kv),))) ||
-            !all(x->isa(x, Union{Tuple,Pair}), kv)
-            throw(ArgumentError("OrderedDict(kv): kv needs to be an iterator of tuples or pairs"))
-        else
-            rethrow(e)
+@static if VERSION >= v"1.11"
+    # see JuliaLang/julia#53151
+    OrderedDict(kv) = dict_with_eltype((K, V) -> OrderedDict{K, V}, kv, eltype(kv))
+else
+    function OrderedDict(kv)
+        try
+            dict_with_eltype((K, V) -> OrderedDict{K, V}, kv, eltype(kv))
+        catch e
+            if isempty(methods(iterate, (typeof(kv),))) ||
+                !all(x->isa(x, Union{Tuple,Pair}), kv)
+                throw(ArgumentError("OrderedDict(kv): kv needs to be an iterator of tuples or pairs"))
+            else
+                rethrow(e)
+            end
         end
     end
 end

test/test_ordered_dict.jl

@@ -507,6 +507,17 @@ using OrderedCollections, Test
         @test del_slots4 == 0
     end
 
+    @testset "Issue #86" begin
+        counter = 0
+        expensive_function(k) = (counter += 1; k > 2 && error("too large!"))
+        @test_throws ErrorException OrderedDict(k => expensive_function(k) for k in 1:3)
+        if VERSION >= v"1.11"
+            @test counter == 3
+        else
+            @test_broken counter == 3  # gives 6 instead
+        end
+    end
+
     @testset "ordered access" begin
         od = OrderedDict(:a=>1, :b=>2, :c=>3)
         @test popfirst!(od) == (:a => 1)