Optimize == for TranformedMesh (#998)

Author: juliohm

src/mesh/cartesiangrid.jl

@@ -162,10 +162,10 @@ function Base.getindex(g::CartesianGrid, I::CartesianIndices)
   CartesianGrid(dims, g.origin, g.spacing, offset)
 end
 
-==(g1::CartesianGrid, g2::CartesianGrid) =
-  g1.topology == g2.topology &&
-  g1.spacing == g2.spacing &&
-  Tuple(g1.origin - g2.origin) == (g1.offset .- g2.offset) .* g1.spacing
+==(g₁::CartesianGrid, g₂::CartesianGrid) =
+  g₁.topology == g₂.topology &&
+  g₁.spacing == g₂.spacing &&
+  Tuple(g₁.origin - g₂.origin) == (g₁.offset .- g₂.offset) .* g₁.spacing
 
 # -----------
 # IO METHODS

src/mesh/transformedmesh.jl

@@ -35,6 +35,8 @@ vertex(m::TransformedMesh, ind::Int) = m.transform(vertex(m.mesh, ind))
 
 centroid(m::TransformedMesh, ind::Int) = m.transform(centroid(m.mesh, ind))
 
+==(m₁::TransformedMesh, m₂::TransformedMesh) = m₁.mesh == m₂.mesh && m₁.transform == m₂.transform
+
 # alias to improve readability in IO methods
 const TransformedGrid{M<:Manifold,C<:CRS,Dim,G<:Grid,TR<:Transform} = TransformedMesh{M,C,GridTopology{Dim},G,TR}
 

test/mesh.jl

@@ -766,6 +766,12 @@
     centr = centroid(tmesh, 1)
     @test @allocated(centroid(tmesh, 1)) < 50
 
+    # optimization of ==
+    trans = Rotate(T(π / 4))
+    cgrid = cartgrid(1000, 1000)
+    tmesh = Meshes.TransformedMesh(cgrid, trans)
+    @test tmesh == tmesh
+
     @test sprint(show, tgrid) == "10×10 TransformedGrid"
     if T == Float32
       @test sprint(show, MIME"text/plain"(), tgrid) == """