ENH: add stringOps::inplaceRemoveSpace()

Style changes:
  - use std algorithm for some stringOps internals
  - pass SubStrings iterators by const reference

ENH: special nullptr handling for ISstream getLine
  - pass through to istream::ignore to support read and discard

applications/test/IFstream/Make/files

@@ -0,0 +1,3 @@
+Test-IFstream.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-IFstream

applications/test/IFstream/Make/options

@@ -0,0 +1,2 @@
+/* EXE_INC = */
+/* EXE_LIBS = */

applications/test/IFstream/Test-IFstream.C

@@ -0,0 +1,105 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2020 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+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 3 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, see <http://www.gnu.org/licenses/>.
+
+Application
+    Test-IFstream
+
+Description
+    Tests on low-level reading
+
+\*---------------------------------------------------------------------------*/
+
+#include "argList.H"
+#include "Fstream.H"
+#include "etcFiles.H"
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+//  Main program:
+
+int main(int argc, char *argv[])
+{
+    argList::noBanner();
+    argList::noParallel();
+
+    #include "setRootCase.H"
+
+    // Test with etc/controlDict (mandatory, from distribution)
+
+    {
+        const fileName inputFile
+        (
+            findEtcFile("controlDict", true, 0007)
+        );
+
+        Info<< nl << "Test getLine" << nl << inputFile << nl;
+        IFstream is(inputFile);
+
+        string buf;
+
+        // Test that buffer resizing works as expected
+
+        Info<< "buf: " << buf.size() << '/' << buf.capacity() << nl;
+
+        bool skipDoc = true;
+
+        while (is.good())
+        {
+            if (skipDoc || is.lineNumber() % 2)
+            {
+                is.getLine(buf);
+
+                Info<< is.lineNumber() << ": "
+                    << buf.size() << '/' << buf.capacity() << ' '
+                    << buf << nl;
+
+                if (buf.starts_with("Documentation"))
+                {
+                    skipDoc = false;
+
+                    Info<< "Found Documentation: skip until closing '}'"
+                        << " line number will now be incorrect"
+                        << nl;
+
+                    auto n = is.getLine(nullptr, '}');
+                    Info<< is.lineNumber() << ": [" << label(n) << "]" << nl;
+                }
+            }
+            else
+            {
+                auto n = is.getLine(nullptr);
+
+                Info<< is.lineNumber() << ": [" << label(n) << "]" << nl;
+            }
+        }
+    }
+
+    Info<< "\nEnd\n" << endl;
+    return 0;
+}
+
+
+// ************************************************************************* //