StaticAssert added

- catch people using silly template sizes for FixedList, PackedList

applications/test/PackedList/PackedListTest.C

@@ -28,6 +28,7 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
+#include "uLabel.H"
 #include "IOstreams.H"
 #include "PackedBoolList.H"
 
@@ -38,7 +39,7 @@ using namespace Foam;
 
 int main(int argc, char *argv[])
 {
-    Info<< "PackedList max_bits() = " << PackedList<0>::max_bits() << nl;
+    Info<< "PackedList max_bits() = " << PackedList<>::max_bits() << nl;
 
     Info<< "\ntest allocation with value\n";
     PackedList<3> list1(5,1);

src/OpenFOAM/containers/Lists/FixedList/FixedList.H

@@ -43,6 +43,7 @@ SourceFiles
 #include "uLabel.H"
 #include "Hash.H"
 #include "autoPtr.H"
+#include "StaticAssert.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -70,6 +71,9 @@ template<class T> class SLList;
 template<class T, unsigned Size>
 class FixedList
 {
+    //- Size must be positive (non-zero) and also fit as a signed value
+    StaticAssert(Size && Size <= INT_MAX);
+
     // Private data
 
         //- Vector of values of type T of size Size.

src/OpenFOAM/containers/Lists/PackedList/PackedList.H

@@ -76,9 +76,6 @@ Note
 SeeAlso
     Foam::DynamicList
 
-ToDo
-    Checks for bad template parameters (ie, nBits=0, nBits too large)?
-
 SourceFiles
     PackedListI.H
     PackedList.C
@@ -89,6 +86,7 @@ SourceFiles
 #define PackedList_H
 
 #include "labelList.H"
+#include "StaticAssert.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -120,6 +118,10 @@ class PackedList
     typedef unsigned int      StorageType;
     typedef List<StorageType> StorageList;
 
+    //- nBits must be positive (non-zero) and fit within the storage
+    //  For simplicity, assume 8-bit bytes
+    StaticAssert(nBits && nBits < (sizeof(StorageType) << 3));
+
     // Private data
 
         //- Number of nBits entries

src/OpenFOAM/db/error/StaticAssert.H

@@ -0,0 +1,87 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software; you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by the
+    Free Software Foundation; either version 2 of the License, or (at your
+    option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM; if not, write to the Free Software Foundation,
+    Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+Class
+    Foam::StaticAssertFailed
+
+Description
+    Macros and classes to provide static (compile-time) assertions.
+
+    Ideas from various sources
+    (http://www.ddj.com/cpp/184401547, http://www.boost.org)
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef StaticAssert_H
+#define StaticAssert_H
+
+namespace Foam
+{
+
+//- Forward declaration of StaticAssertionFailed.
+//  Leave as an incomplete class so that sizeof(..) fails
+template<bool Truth> class StaticAssertionFailed;
+
+/*---------------------------------------------------------------------------*\
+                    Class StaticAssertionFailed Declaration
+\*---------------------------------------------------------------------------*/
+
+//- Specialization for successful assertions
+template<>
+class StaticAssertionFailed<true>
+{};
+
+
+//- Helper class for handling static assertions
+template<unsigned Test>
+class StaticAssertionTest {};
+
+}
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// internal use:
+// ~~~~~~~~~~~~~
+// paste together strings, even if an argument is itself a macro
+#define StaticAssertMacro(X,Y)  StaticAssertMacro1(X,Y)
+#define StaticAssertMacro1(X,Y) StaticAssertMacro2(X,Y)
+#define StaticAssertMacro2(X,Y) X##Y
+
+// external use:
+// ~~~~~~~~~~~~~
+/**
+ * @def StaticAssert(Test)
+ * Assert that some test is true at compile-time
+*/
+#define StaticAssert(Test)                                                   \
+    typedef ::Foam::StaticAssertionTest                                      \
+    <                                                                        \
+        sizeof( ::Foam::StaticAssertionFailed< ((Test) ? true : false) > )   \
+    > StaticAssertMacro(StaticAssertionTest, __LINE__)
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //