Add support for RelativeGap attribute (#111)

Author: odow

src/MOI_wrapper.jl

@@ -1763,6 +1763,13 @@ function MOI.get(model::Optimizer, ::MOI.SolveTimeSec)
     return Highs_getRunTime(model)
 end
 
+function MOI.get(model::Optimizer, ::MOI.RelativeGap)
+    p = Ref{Cdouble}(0)
+    ret = Highs_getDoubleInfoValue(model, "mip_gap", p)
+    _check_ret(ret)
+    return p[]
+end
+
 function MOI.get(model::Optimizer, ::MOI.SimplexIterations)
     p = Ref{HighsInt}(0)
     ret = Highs_getIntInfoValue(model, "simplex_iteration_count", p)

test/MOI_wrapper.jl

@@ -253,6 +253,13 @@ function _knapsack_model(; mip::Bool, solver::String)
     return model
 end
 
+function test_RelativeGap()
+    model = _knapsack_model(mip = true, solver = "choose")
+    MOI.optimize!(model)
+    @test MOI.get(model, MOI.RelativeGap()) ≈ 0.0
+    return
+end
+
 function test_SimplexIterations_BarrierIterations()
     model = _knapsack_model(mip = false, solver = "simplex")
     @test MOI.get(model, MOI.SimplexIterations()) == 0