ENH: add StaticAssert to Polynomial - positive number of terms only

ENH: allow construct from UList of coefficients, from C-arrays
     avoid uninitialized values for null constructor

src/OpenFOAM/primitives/functions/Polynomial/Polynomial.C

@@ -33,7 +33,50 @@ Foam::Polynomial<PolySize>::Polynomial()
     VectorSpace<Polynomial<PolySize>, scalar, PolySize>(),
     logActive_(false),
     logCoeff_(0.0)
-{}
+{
+    for (int i = 0; i < PolySize; ++i)
+    {
+        this->v_[i] = 0.0;
+    }
+}
+
+
+template<int PolySize>
+Foam::Polynomial<PolySize>::Polynomial(const scalar coeffs[PolySize])
+:
+    VectorSpace<Polynomial<PolySize>, scalar, PolySize>(),
+    logActive_(false),
+    logCoeff_(0.0)
+{
+    for (int i=0; i<PolySize; i++)
+    {
+        this->v_[i] = coeffs[i];
+    }
+}
+
+
+template<int PolySize>
+Foam::Polynomial<PolySize>::Polynomial(const UList<scalar>& coeffs)
+:
+    VectorSpace<Polynomial<PolySize>, scalar, PolySize>(),
+    logActive_(false),
+    logCoeff_(0.0)
+{
+    if (coeffs.size() != PolySize)
+    {
+        FatalErrorIn
+        (
+            "Polynomial<PolySize>::Polynomial(const UList<scalar>&)"
+        )   << "Size mismatch: Needed " << PolySize
+            << " but got " << coeffs.size()
+            << nl << exit(FatalError);
+    }
+
+    for (int i = 0; i < PolySize; ++i)
+    {
+        this->v_[i] = coeffs[i];
+    }
+}
 
 
 template<int PolySize>
@@ -173,13 +216,9 @@ Foam::Polynomial<PolySize>::integrateMinus1(const scalar intConstant)
     }
 
     newCoeffs[0] = intConstant;
-
-    if (PolySize > 0)
+    for (label i=1; i<PolySize; ++i)
     {
-        for (label i=1; i<PolySize; i++)
-        {
-            newCoeffs[i] = this->v_[i]/i;
-        }
+        newCoeffs[i] = this->v_[i]/i;
     }
 
     return newCoeffs;

src/OpenFOAM/primitives/functions/Polynomial/Polynomial.H

@@ -29,7 +29,7 @@ Description
 
         poly = logCoeff*log(x) + sum(coeff_[i]*x^i)
 
-    where 0 <= i <= n
+    where 0 \<= i \<= n
 
     - integer powers, starting at zero
     - evaluate(x) to evaluate the poly for a given value
@@ -51,6 +51,7 @@ SourceFiles
 #include "scalar.H"
 #include "Ostream.H"
 #include "VectorSpace.H"
+#include "StaticAssert.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -79,6 +80,9 @@ class Polynomial
 :
     public VectorSpace<Polynomial<PolySize>, scalar, PolySize>
 {
+    //- Size must be positive (non-zero)
+    StaticAssert(PolySize > 0);
+
     // Private data
 
         //- Include the log term? - only activated using integrateMinus1()
@@ -97,9 +101,15 @@ public:
 
     // Constructors
 
-        //- Construct null
+        //- Construct null, with all coefficients = 0.0
         Polynomial();
 
+        //- Construct from C-array of coefficients
+        explicit Polynomial(const scalar coeffs[PolySize]);
+
+        //- Construct from a list of coefficients
+        explicit Polynomial(const UList<scalar>& coeffs);
+
         //- Construct from name and Istream
         Polynomial(const word& name, Istream& is);