ENH: additional dimensionedType constructors

- construct from dimensioned/value, defaulting name from value.
  Can be convenient for these type of operations:

      max(.., dimensionedScalar(somedims, 0.5))

- construct from dimensioned/one, forwarding to pTraits::one.
  Can be convenient for constructors:

    volScalarField( ..., dimensionedScalar(somedims, one{}))

ENH: minor updates to zero/one classes.

- add global 'One' constant for symmetry with 'Zero'.

src/OpenFOAM/dimensionedTypes/dimensionedType/dimensionedType.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2019 OpenCFD Ltd.
+    Copyright (C) 2016-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -46,7 +46,7 @@ void Foam::dimensioned<Type>::initialize(Istream& is, const bool checkDims)
         is.putBack(nextToken);
     }
 
-    scalar mult(1.0);
+    scalar mult{1};
 
     if (nextToken == token::BEGIN_SQR)
     {
@@ -128,7 +128,11 @@ Foam::dimensioned<Type>::dimensioned(const dimensionSet& dims)
 
 
 template<class Type>
-Foam::dimensioned<Type>::dimensioned(const dimensionSet& dims, const zero)
+Foam::dimensioned<Type>::dimensioned
+(
+    const dimensionSet& dims,
+    const Foam::zero
+)
 :
     name_("0"),
     dimensions_(dims),
@@ -139,13 +143,26 @@ Foam::dimensioned<Type>::dimensioned(const dimensionSet& dims, const zero)
 template<class Type>
 Foam::dimensioned<Type>::dimensioned
 (
-    const word& name,
+    const dimensionSet& dims,
-    const dimensioned<Type>& dt
+    const Foam::one
 )
 :
-    name_(name),
+    name_("1"),
-    dimensions_(dt.dimensions_),
+    dimensions_(dims),
-    value_(dt.value_)
+    value_(pTraits<Type>::one)
+{}
+
+
+template<class Type>
+Foam::dimensioned<Type>::dimensioned
+(
+    const dimensionSet& dims,
+    const Type& val
+)
+:
+    name_(::Foam::name(val)),
+    dimensions_(dims),
+    value_(val)
 {}
 
 
@@ -163,6 +180,19 @@ Foam::dimensioned<Type>::dimensioned
 {}
 
 
+template<class Type>
+Foam::dimensioned<Type>::dimensioned
+(
+    const word& name,
+    const dimensioned<Type>& dt
+)
+:
+    name_(name),
+    dimensions_(dt.dimensions_),
+    value_(dt.value_)
+{}
+
+
 template<class Type>
 Foam::dimensioned<Type>::dimensioned
 (
@@ -490,7 +520,7 @@ Foam::Istream& Foam::dimensioned<Type>::read(Istream& is, const bool readName)
     }
 
     // Read dimensionSet + multiplier
-    scalar mult(1.0);
+    scalar mult{1};
     dimensions_.read(is, mult);
 
     // Read value
@@ -510,7 +540,7 @@ Foam::dimensioned<Type>::read(Istream& is, const dictionary& readSet)
     is >> name_;
 
     // Read dimensionSet + multiplier
-    scalar mult(1.0);
+    scalar mult{1};
     dimensions_.read(is, mult, readSet);
 
     // Read value
@@ -533,7 +563,7 @@ Foam::Istream& Foam::dimensioned<Type>::read
     is >> name_;
 
     // Read dimensionSet + multiplier
-    scalar mult(1.0);
+    scalar mult{1};
     dimensions_.read(is, mult, readSet);
 
     // Read value
@@ -561,7 +591,7 @@ void Foam::dimensioned<Type>::writeEntry
     }
 
     // The dimensions
-    scalar mult(1.0);
+    scalar mult{1};
     dimensions_.write(os, mult);
 
     // The value
@@ -777,7 +807,7 @@ Foam::Ostream& Foam::operator<<(Ostream& os, const dimensioned<Type>& dt)
     os << dt.name() << token::SPACE;
 
     // The dimensions
-    scalar mult(1.0);
+    scalar mult{1};
     dt.dimensions().write(os, mult);
 
     // The value

src/OpenFOAM/dimensionedTypes/dimensionedType/dimensionedType.H

@@ -48,7 +48,8 @@ SourceFiles
 namespace Foam
 {
 
-// Forward declarations
+// Forward Declarations
+class one;
 class zero;
 class dictionary;
 class primitiveEntry;
@@ -58,7 +59,6 @@ template<class Type> class dimensioned;
 template<class Type>
 Istream& operator>>(Istream& is, dimensioned<Type>& dt);
 
-
 /*---------------------------------------------------------------------------*\
                            Class dimensioned Declaration
 \*---------------------------------------------------------------------------*/
@@ -130,7 +130,10 @@ public:
         explicit dimensioned(const dimensionSet& dims);
 
         //- A dimensioned Zero, named "0"
-        explicit dimensioned(const dimensionSet& dims, const zero);
+        explicit dimensioned(const dimensionSet& dims, const Foam::zero);
+
+        //- A dimensioned pTraits::one, named "1"
+        explicit dimensioned(const dimensionSet& dims, const Foam::one);
 
         //- Implicit construct dimensionless from given value.
         dimensioned(const Type& val)
@@ -140,8 +143,8 @@ public:
             value_(val)
         {}
 
-        //- Copy construct dimensioned Type with a new name
+        //- Construct dimensioned from given value
-        dimensioned(const word& name, const dimensioned<Type>& dt);
+        dimensioned(const dimensionSet& dims, const Type& val);
 
         //- Construct from components (name, dimensions, value).
         dimensioned
@@ -151,6 +154,9 @@ public:
             const Type& val
         );
 
+        //- Copy construct dimensioned Type with a new name
+        dimensioned(const word& name, const dimensioned<Type>& dt);
+
         //- Construct from primitive entry with given name.
         //  The entry may contain optional name and dimensions.
         //  \verbatim
@@ -234,7 +240,7 @@ public:
     // Static Member Functions
 
         //- Construct dimensioned from dictionary, with default value.
-        //- FatalIOError if there are excess tokens.
+        //  FatalIOError if there are excess tokens.
         static dimensioned<Type> getOrDefault
         (
             const word& name,

src/OpenFOAM/primitives/one/one.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017 OpenCFD Ltd.
+    Copyright (C) 2017-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,8 +28,9 @@ Class
     Foam::one
 
 Description
-    A class representing the concept of 1 (one), which can be used to avoid
+    A class representing the concept of 1 (one) that can be used to avoid
-    manipulating objects that are known to be \em one at compile-time.
+    manipulating objects known to be \em one at compile-time.
+    It is also used for tagged dispatch.
 
 SourceFiles
     oneI.H
@@ -49,7 +50,7 @@ SeeAlso
 namespace Foam
 {
 
-// Forward declarations
+// Forward Declarations
 class one;
 class Istream;
 class Ostream;
@@ -61,13 +62,14 @@ class Ostream;
 class one
 {
 public:
+
     typedef one value_type;
 
-    // Forward declarations
+    // Forward Declarations
     class minus;
     class null;
 
-    //- Null constructible
+    //- Default construct
     constexpr one() noexcept {}
 
     //- Construct from Istream consumes no content.
@@ -75,19 +77,19 @@ public:
 
 
     //- Return 1 for label
-    inline constexpr operator label() const noexcept
+    constexpr operator label() const noexcept
     {
         return 1;
     }
 
     //- Return 1 for float
-    inline constexpr operator float() const noexcept
+    constexpr operator float() const noexcept
     {
         return 1;
     }
 
     //- Return 1 for double
-    inline constexpr operator double() const noexcept
+    constexpr operator double() const noexcept
     {
         return 1;
     }
@@ -99,14 +101,15 @@ public:
 \*---------------------------------------------------------------------------*/
 
 //- A class representing the concept of -1.
-//  Note that this class must never be derived from 'one', since this could
+//  \note this class must never be derived from Foam::one, since this could
 //  potentially mask its behaviour.
 class one::minus
 {
 public:
+
     typedef minus value_type;
 
-    //- Null constructible
+    //- Default construct
     constexpr minus() noexcept {}
 
     //- Construct from Istream consumes no content.
@@ -114,19 +117,19 @@ public:
 
 
     //- Return -1 for label
-    inline constexpr operator label() const noexcept
+    constexpr operator label() const noexcept
     {
         return -1;
     }
 
     //- Return -1 for float
-    inline constexpr operator float() const noexcept
+    constexpr operator float() const noexcept
     {
         return -1;
     }
 
     //- Return -1 for double
-    inline constexpr operator double() const noexcept
+    constexpr operator double() const noexcept
     {
         return -1;
     }
@@ -137,15 +140,16 @@ public:
                           Class one::null Declaration
 \*---------------------------------------------------------------------------*/
 
-//- A one class with a null output adapter.
+//- A Foam::one class with a null output adapter.
 class one::null
 :
     public one
 {
 public:
+
     typedef null value_type;
 
-    //- Null constructible
+    //- Default construct
     constexpr null() noexcept {}
 
     //- Construct from Istream consumes no content.
@@ -155,6 +159,9 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+//- Global one (1)
+static constexpr const one One;
+
 // IOstream Operators
 
 //- Read from Istream consumes no content.
@@ -182,6 +189,7 @@ inline constexpr Ostream& operator<<(Ostream& os, const one::null&) noexcept
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+// Global Operators, Functions
 #include "oneI.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

src/OpenFOAM/primitives/zero/zero.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2019 OpenCFD Ltd.
+    Copyright (C) 2017-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,8 +28,9 @@ Class
     Foam::zero
 
 Description
-    A class representing the concept of 0 (zero), which can be used to avoid
+    A class representing the concept of 0 (zero) that can be used to avoid
-    manipulating objects that are known to be \em zero at compile-time.
+    manipulating objects known to be \em zero at compile-time.
+    It is also used for tagged dispatch.
 
 SourceFiles
     zero.C
@@ -50,7 +51,7 @@ SeeAlso
 namespace Foam
 {
 
-// Forward declarations
+// Forward Declarations
 class zero;
 class Istream;
 class Ostream;
@@ -62,12 +63,13 @@ class Ostream;
 class zero
 {
 public:
+
     typedef zero value_type;
 
-    // Forward declarations
+    // Forward Declarations
     class null;
 
-    //- Null constructible
+    //- Default construct
     constexpr zero() noexcept {}
 
     //- Construct from Istream consumes no content.
@@ -75,25 +77,25 @@ public:
 
 
     //- Return false (0) for bool
-    inline constexpr operator bool() const noexcept
+    constexpr operator bool() const noexcept
     {
         return false;
     }
 
     //- Return 0 for label
-    inline constexpr operator label() const noexcept
+    constexpr operator label() const noexcept
     {
         return 0;
     }
 
     //- Return 0 for float
-    inline constexpr operator float() const noexcept
+    constexpr operator float() const noexcept
     {
         return 0;
     }
 
     //- Return 0 for double
-    inline constexpr operator double() const noexcept
+    constexpr operator double() const noexcept
     {
         return 0;
     }
@@ -110,6 +112,7 @@ class zero::null
     public zero
 {
 public:
+
     typedef null value_type;
 
     //- A static zero::null for dereferencing as a dummy element
@@ -125,7 +128,7 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-//- Global zero
+//- Global zero (0)
 static constexpr const zero Zero;
 
 // IOstream Operators
@@ -149,6 +152,7 @@ inline constexpr Ostream& operator<<(Ostream& os, const zero::null&) noexcept
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+// Global Operators, Functions
 #include "zeroI.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //