Add MOI.attribute_value_type

docs/src/reference/models.md

@@ -18,6 +18,7 @@ get
 get!
 set
 supports
+attribute_value_type
 ```
 
 ## Model interface

docs/src/tutorials/implementing.md

@@ -271,6 +271,11 @@ For each attribute
  * [`supports`](@ref) returns a `Bool` indicating whether the solver supports the
    attribute.
 
+!!! info
+    Use [`attribute_value_type`](@ref) to check the value expected by a given
+    attribute. You should make sure that your [`get`](@ref) function correctly
+    infers to this type (or a subtype of it).
+
 Each column in the table indicates whether you need to implement the particular
 method for each attribute.
 

src/Bridges/Constraint/bridge.jl

@@ -27,10 +27,10 @@ function bridge_constraint end
 
 The number of variables created by the bridge `b` in the model.
 """
-MOI.get(::AbstractBridge, ::MOI.NumberOfVariables) = 0
+MOI.get(::AbstractBridge, ::MOI.NumberOfVariables)::Int64 = 0
 
 """
-    MOI.get(b::AbstractBridge, ::MOI.NumberOfVariables)
+    MOI.get(b::AbstractBridge, ::MOI.ListOfVariableIndices)
 
 The list of variables created by the bridge `b` in the model.
 """

src/Bridges/Constraint/det.jl

@@ -210,7 +210,10 @@ function subsum(
 end
 
 # Attributes, Bridge acting as a model
-MOI.get(b::LogDetBridge, ::MOI.NumberOfVariables) = length(b.Δ) + length(b.l)
+
+function MOI.get(b::LogDetBridge, ::MOI.NumberOfVariables)::Int64
+    return length(b.Δ) + length(b.l)
+end
 
 MOI.get(b::LogDetBridge, ::MOI.ListOfVariableIndices) = [b.Δ; b.l]
 
@@ -220,21 +223,21 @@ function MOI.get(
         MOI.VectorAffineFunction{T},
         MOI.PositiveSemidefiniteConeTriangle,
     },
-) where {T}
+)::Int64 where {T}
     return 1
 end
 
 function MOI.get(
     b::LogDetBridge{T},
     ::MOI.NumberOfConstraints{MOI.VectorAffineFunction{T},MOI.ExponentialCone},
-) where {T}
+)::Int64 where {T}
     return length(b.lcindex)
 end
 
 function MOI.get(
     ::LogDetBridge{T},
     ::MOI.NumberOfConstraints{MOI.ScalarAffineFunction{T},MOI.LessThan{T}},
-) where {T}
+)::Int64 where {T}
     return 1
 end
 
@@ -407,7 +410,8 @@ function MOIB.added_constraint_types(::Type{RootDetBridge{T}}) where {T}
 end
 
 # Attributes, Bridge acting as a model
-MOI.get(b::RootDetBridge, ::MOI.NumberOfVariables) = length(b.Δ)
+
+MOI.get(b::RootDetBridge, ::MOI.NumberOfVariables)::Int64 = length(b.Δ)
 
 MOI.get(b::RootDetBridge, ::MOI.ListOfVariableIndices) = copy(b.Δ)
 
@@ -417,7 +421,7 @@ function MOI.get(
         MOI.VectorAffineFunction{T},
         MOI.PositiveSemidefiniteConeTriangle,
     },
-) where {T}
+)::Int64 where {T}
     return 1
 end
 
@@ -427,7 +431,7 @@ function MOI.get(
         MOI.VectorAffineFunction{T},
         MOI.GeometricMeanCone,
     },
-) where {T}
+)::Int64 where {T}
     return 1
 end
 

src/Bridges/Constraint/functionize.jl

@@ -54,7 +54,7 @@ end
 function MOI.get(
     ::ScalarFunctionizeBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.ScalarAffineFunction{T},S},
-) where {T,S}
+)::Int64 where {T,S}
     return 1
 end
 
@@ -158,7 +158,7 @@ end
 function MOI.get(
     ::VectorFunctionizeBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.VectorAffineFunction{T},S},
-) where {T,S}
+)::Int64 where {T,S}
     return 1
 end
 

src/Bridges/Constraint/geomean.jl

@@ -164,29 +164,29 @@ function concrete_bridge_type(
 end
 
 # Attributes, Bridge acting as a model
-MOI.get(b::GeoMeanBridge, ::MOI.NumberOfVariables) = length(b.xij)
+MOI.get(b::GeoMeanBridge, ::MOI.NumberOfVariables)::Int64 = length(b.xij)
 
 MOI.get(b::GeoMeanBridge, ::MOI.ListOfVariableIndices) = copy(b.xij)
 
 function MOI.get(
     ::GeoMeanBridge{T,F},
     ::MOI.NumberOfConstraints{F,MOI.LessThan{T}},
-) where {T,F}
+)::Int64 where {T,F}
     return 1 # t ≤ x_{l1}/sqrt(N)
 end
 
 function MOI.get(
     b::GeoMeanBridge{T,F,G},
     ::MOI.NumberOfConstraints{G,MOI.RotatedSecondOrderCone},
-) where {T,F,G}
+)::Int64 where {T,F,G}
     return length(b.socrc)
 end
 
 function MOI.get(
     b::GeoMeanBridge{T,F,G},
     ::MOI.NumberOfConstraints{G,MOI.Nonnegatives},
-) where {T,F,G}
-    return (b.d > 2 ? 0 : 1)
+)::Int64 where {T,F,G}
+    return b.d > 2 ? 0 : 1
 end
 
 function MOI.get(

src/Bridges/Constraint/geomean_to_relentr.jl

@@ -86,7 +86,7 @@ function concrete_bridge_type(
 end
 
 # Attributes, Bridge acting as a model
-MOI.get(bridge::GeoMeantoRelEntrBridge, ::MOI.NumberOfVariables) = 1
+MOI.get(::GeoMeantoRelEntrBridge, ::MOI.NumberOfVariables)::Int64 = 1
 
 function MOI.get(bridge::GeoMeantoRelEntrBridge, ::MOI.ListOfVariableIndices)
     return [bridge.y]
@@ -95,14 +95,14 @@ end
 function MOI.get(
     ::GeoMeantoRelEntrBridge{T,F},
     ::MOI.NumberOfConstraints{F,MOI.Nonnegatives},
-) where {T,F}
+)::Int64 where {T,F}
     return 1
 end
 
 function MOI.get(
     ::GeoMeantoRelEntrBridge{T,F,G},
     ::MOI.NumberOfConstraints{G,MOI.RelativeEntropyCone},
-) where {T,F,G}
+)::Int64 where {T,F,G}
     return 1
 end
 

src/Bridges/Constraint/indicator_sos.jl

@@ -154,9 +154,7 @@ end
 
 # Attributes, Bridge acting as a model
 
-function MOI.get(::IndicatorSOS1Bridge, ::MOI.NumberOfVariables)
-    return 1
-end
+MOI.get(::IndicatorSOS1Bridge, ::MOI.NumberOfVariables)::Int64 = 1
 
 function MOI.get(b::IndicatorSOS1Bridge, ::MOI.ListOfVariableIndices)
     return [b.w_variable]
@@ -165,28 +163,28 @@ end
 function MOI.get(
     ::IndicatorSOS1Bridge{T,BC,Nothing},
     ::MOI.NumberOfConstraints{MOI.SingleVariable,BC},
-) where {T,BC}
+)::Int64 where {T,BC}
     return 0
 end
 
 function MOI.get(
     ::IndicatorSOS1Bridge{T,BC,CI},
     ::MOI.NumberOfConstraints{MOI.SingleVariable,BC},
-) where {T,BC,CI<:MOI.ConstraintIndex{MOI.SingleVariable,BC}}
+)::Int64 where {T,BC,CI<:MOI.ConstraintIndex{MOI.SingleVariable,BC}}
     return 1
 end
 
 function MOI.get(
     ::IndicatorSOS1Bridge,
     ::MOI.NumberOfConstraints{MOI.VectorOfVariables,<:MOI.SOS1},
-)
+)::Int64
     return 1
 end
 
 function MOI.get(
     ::IndicatorSOS1Bridge{T,BC},
     ::MOI.NumberOfConstraints{MOI.ScalarAffineFunction{T},BC},
-) where {T,BC,CI<:MOI.ConstraintIndex{MOI.SingleVariable,BC}}
+)::Int64 where {T,BC,CI<:MOI.ConstraintIndex{MOI.SingleVariable,BC}}
     return 1
 end
 

src/Bridges/Constraint/interval.jl

@@ -86,14 +86,14 @@ end
 function MOI.get(
     ::SplitIntervalBridge{T,F,S,LS},
     ::MOI.NumberOfConstraints{F,LS},
-) where {T,F,S,LS}
+)::Int64 where {T,F,S,LS}
     return 1
 end
 
 function MOI.get(
     ::SplitIntervalBridge{T,F,S,LS,US},
     ::MOI.NumberOfConstraints{F,US},
-) where {T,F,S,LS,US}
+)::Int64 where {T,F,S,LS,US}
     return 1
 end
 

src/Bridges/Constraint/norm_spec_nuc_to_psd.jl

@@ -70,9 +70,9 @@ end
 
 # Attributes, Bridge acting as a model
 function MOI.get(
-    bridge::NormSpectralBridge{T,F,G},
+    ::NormSpectralBridge{T,F,G},
     ::MOI.NumberOfConstraints{F,MOI.PositiveSemidefiniteConeTriangle},
-) where {T,F,G}
+)::Int64 where {T,F,G}
     return 1
 end
 
@@ -282,7 +282,7 @@ function concrete_bridge_type(
 end
 
 # Attributes, Bridge acting as a model
-function MOI.get(bridge::NormNuclearBridge, ::MOI.NumberOfVariables)
+function MOI.get(bridge::NormNuclearBridge, ::MOI.NumberOfVariables)::Int64
     return length(bridge.U) + length(bridge.V)
 end
 
@@ -291,16 +291,16 @@ function MOI.get(bridge::NormNuclearBridge, ::MOI.ListOfVariableIndices)
 end
 
 function MOI.get(
-    bridge::NormNuclearBridge{T,F,G,H},
+    ::NormNuclearBridge{T,F,G,H},
     ::MOI.NumberOfConstraints{F,MOI.GreaterThan{T}},
-) where {T,F,G,H}
+)::Int64 where {T,F,G,H}
     return 1
 end
 
 function MOI.get(
-    bridge::NormNuclearBridge{T,F,G,H},
+    ::NormNuclearBridge{T,F,G,H},
     ::MOI.NumberOfConstraints{G,MOI.PositiveSemidefiniteConeTriangle},
-) where {T,F,G,H}
+)::Int64 where {T,F,G,H}
     return 1
 end
 

src/Bridges/Constraint/norm_to_lp.jl

@@ -150,12 +150,14 @@ function concrete_bridge_type(
 end
 
 # Attributes, Bridge acting as a model
-MOI.get(b::NormOneBridge, ::MOI.NumberOfVariables) = length(b.y)
+MOI.get(b::NormOneBridge, ::MOI.NumberOfVariables)::Int64 = length(b.y)
+
 MOI.get(b::NormOneBridge, ::MOI.ListOfVariableIndices) = copy(b.y)
+
 function MOI.get(
-    b::NormOneBridge{T,F},
+    ::NormOneBridge{T,F},
     ::MOI.NumberOfConstraints{F,MOI.Nonnegatives},
-) where {T,F}
+)::Int64 where {T,F}
     return 1
 end
 

src/Bridges/Constraint/quad_to_soc.jl

@@ -189,7 +189,7 @@ function MOI.get(
         MOI.VectorAffineFunction{T},
         MOI.RotatedSecondOrderCone,
     },
-) where {T}
+)::Int64 where {T}
     return 1
 end
 

src/Bridges/Constraint/relentr_to_exp.jl

@@ -82,7 +82,7 @@ function concrete_bridge_type(
 end
 
 # Attributes, Bridge acting as a model
-function MOI.get(bridge::RelativeEntropyBridge, ::MOI.NumberOfVariables)
+function MOI.get(bridge::RelativeEntropyBridge, ::MOI.NumberOfVariables)::Int64
     return length(bridge.y)
 end
 
@@ -91,16 +91,16 @@ function MOI.get(bridge::RelativeEntropyBridge, ::MOI.ListOfVariableIndices)
 end
 
 function MOI.get(
-    bridge::RelativeEntropyBridge{T,F},
+    ::RelativeEntropyBridge{T,F},
     ::MOI.NumberOfConstraints{F,MOI.GreaterThan{T}},
-) where {T,F}
+)::Int64 where {T,F}
     return 1
 end
 
 function MOI.get(
     bridge::RelativeEntropyBridge{T,F,G},
     ::MOI.NumberOfConstraints{G,MOI.ExponentialCone},
-) where {T,F,G}
+)::Int64 where {T,F,G}
     return length(bridge.y)
 end
 

src/Bridges/Constraint/scalarize.jl

@@ -58,7 +58,7 @@ end
 function MOI.get(
     bridge::ScalarizeBridge{T,F,S},
     ::MOI.NumberOfConstraints{F,S},
-) where {T,F,S}
+)::Int64 where {T,F,S}
     return length(bridge.scalar_constraints)
 end
 

src/Bridges/Constraint/semi_to_binary.jl

@@ -214,9 +214,7 @@ end
 
 # Attributes, Bridge acting as a model
 
-function MOI.get(::SemiToBinaryBridge, ::MOI.NumberOfVariables)
-    return 1
-end
+MOI.get(::SemiToBinaryBridge, ::MOI.NumberOfVariables)::Int64 = 1
 
 function MOI.get(b::SemiToBinaryBridge, ::MOI.ListOfVariableIndices)
     return [b.binary_variable]
@@ -225,28 +223,28 @@ end
 function MOI.get(
     ::SemiToBinaryBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.SingleVariable,MOI.ZeroOne},
-) where {T,S}
+)::Int64 where {T,S}
     return 1
 end
 
 function MOI.get(
     ::SemiToBinaryBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.SingleVariable,MOI.Integer},
-) where {T,S<:MOI.Semiinteger}
+)::Int64 where {T,S<:MOI.Semiinteger}
     return 1
 end
 
 function MOI.get(
     ::SemiToBinaryBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.ScalarAffineFunction{T},MOI.GreaterThan{T}},
-) where {T,S}
+)::Int64 where {T,S}
     return 1
 end
 
 function MOI.get(
     ::SemiToBinaryBridge{T,S},
     ::MOI.NumberOfConstraints{MOI.ScalarAffineFunction{T},MOI.LessThan{T}},
-) where {T,S}
+)::Int64 where {T,S}
     return 1
 end
 

src/Bridges/Constraint/set_map.jl

@@ -64,7 +64,7 @@ end
 function MOI.get(
     ::SetMapBridge{T,S2,S1,F},
     ::MOI.NumberOfConstraints{F,S2},
-) where {T,S2,S1,F}
+)::Int64 where {T,S2,S1,F}
     return 1
 end