fix for older julia versions

Author: rafaqz

src/libproj.jl

@@ -490,10 +490,17 @@ function proj_degree_output(P, dir)
     @ccall libproj.proj_degree_output(P::Ptr{PJ}, dir::PJ_DIRECTION)::Cint
 end
 
-proj_trans(P, direction, coord) = proj_trans(P, direction, Coord(coord))
-function proj_trans(P, direction, coord::Coord{N}) where N 
-    @ccall libproj.proj_trans(P::Ptr{PJ}, direction::PJ_DIRECTION, coord::Coord{N})::Coord{N}
-end
+# In older Julia versions `@ccall` fails silently on `Coord{N}` input
+# So we temporarily unrap it as an NTuple and rewrap. 
+# This *should* have no overhead.
+#
+# When there is a new LTS we can remove these specialisations
+function proj_trans(P, direction, coord::Coord{N}) where N
+    coord1 = (coord.x, coord.y, coord.z, coord.t)
+    @ccall libproj.proj_trans(P::Ptr{PJ}, direction::PJ_DIRECTION, coord1::NTuple{4,Float64})::Coord{N}
+end
+# Accept other types
+proj_trans(P, direction, coord) = proj_trans(P, direction, Coord(coord...))
 
 function proj_trans_get_last_used_operation(P)
     @ccall libproj.proj_trans_get_last_used_operation(P::Ptr{PJ})::Ptr{PJ}

test/libproj.jl

@@ -104,13 +104,11 @@ end
 
     # transform to UTM zone 32
     b = Proj.proj_trans(pj, Proj.PJ_FWD, a)
-    @show b
     @test is_approx(b, (691875.632, 6098907.825, 0.0, Inf))
 
     # inverse transform, back to geographical
-    b = Proj.proj_trans(pj, Proj.PJ_INV, b)
-    @show b
-    @test is_approx(b, (12.0, 55.0, 0.0, Inf))
+    c = Proj.proj_trans(pj, Proj.PJ_INV, b)
+    @test is_approx(c, (12.0, 55.0, 0.0, Inf))
 
     # Clean up
     pj = Proj.proj_destroy(pj)

test/runtests.jl

@@ -8,5 +8,4 @@ is_approx(a, b) = all(isapprox(c[1], c[2]) for c in zip(a, b))
 @testset "Proj" begin
     include("libproj.jl")
     include("applications.jl")
-
-end # testset "Proj"
+end