Fix allocations

Author: YingboMa

src/solve.jl

@@ -60,7 +60,7 @@ function DiffEqBase.init(prob::NonlinearProblem{uType, iip}, alg::AbstractNewton
     fu = f(u, p)
   end
 
-  
+
   sol = build_newton_solution(u, Val(iip))
   if immutable
     return NewtonImmutableSolver(1, f, alg, u, fu, p, nothing, false, maxiters, internalnorm, :Default, tol, sol)
@@ -81,7 +81,7 @@ function DiffEqBase.solve!(solver::AbstractNonlinearSolver)
   if solver.iter == solver.maxiters
     solver.retcode = :MaxitersExceeded
   end
-  set_solution!(solver)
+  solver = set_solution(solver)
   return solver.sol
 end
 
@@ -151,19 +151,25 @@ function check_for_exact_solution!(solver::BracketingSolver)
   return false
 end
 
-function set_solution!(solver::BracketingSolver)
-  solver.sol.left = solver.left
-  solver.sol.right = solver.right
-  solver.sol.retcode = solver.retcode
+function set_solution(solver::BracketingSolver)
+  sol = solver.sol
+  @set! sol.left = solver.left
+  @set! sol.right = solver.right
+  @set! sol.retcode = solver.retcode
+  @set! solver.sol = sol
+  return solver
 end
 
 function get_solution(solver::BracketingImmutableSolver)
   return (left = solver.left, right = solver.right, retcode = solver.retcode)
 end
 
-function set_solution!(solver::NewtonSolver)
-  solver.sol.u = solver.u
-  solver.sol.retcode = solver.retcode
+function set_solution(solver::NewtonSolver)
+  sol = solver.sol
+  @set! sol.u = solver.u
+  @set! sol.retcode = solver.retcode
+  @set! solver.sol = sol
+  return solver
 end
 
 function get_solution(solver::NewtonImmutableSolver)

src/types.jl

@@ -83,7 +83,7 @@ function build_solution(u_prototype, ::Val{false})
     return BracketingSolution(zero(u_prototype), zero(u_prototype), :Default)
 end
 
-mutable struct NewtonSolution{uType}
+struct NewtonSolution{uType}
     u::uType
     retcode::Symbol
 end

test/runtests.jl

@@ -29,6 +29,6 @@ sol = benchmark_mutable(f, u0)
 sol = benchmark_scalar(sf, su0)
 @test sol * sol - 2 < 1e-9
 
-@test_broken (@ballocated benchmark_immutable($f, $u0)) == 0
-@test_broken (@ballocated benchmark_mutable($f, $u0)) == 0
+@test (@ballocated benchmark_immutable($f, $u0)) == 0
+@test (@ballocated benchmark_mutable($f, $u0)) < 200
 @test (@ballocated benchmark_scalar($sf, $su0)) == 0