STYLE: Modernize to C++11 conventions

STYLE: Use auto for variable creation

This check is responsible for using the auto type specifier for variable
declarations to improve code readability and maintainability.

The auto type specifier will only be introduced in situations where the
variable type matches the type of the initializer expression. In other words
auto should deduce the same type that was originally spelled in the source

cd /Users/johnsonhj/Dashboard/src/ITK-clangtidy/
run-clang-tidy.py -checks=-*,modernize-use-auto  -header-filter=.* -fix

use auto when declaring iterators
use auto when initializing with a cast to avoid duplicating the type name
use auto when initializing with a template cast to avoid duplicating the type name
use auto when initializing with new to avoid duplicating the type name

SRCDIR=/Users/johnsonhj/Dashboard/src/ITK #My local SRC
BLDDIR=/Users/johnsonhj/Dashboard/src/ITK-clangtidy/ #My local BLD

PERF: Replace explicit return calls of constructor

Replaces explicit calls to the constructor in a return with a braced
initializer list. This way the return type is not needlessly duplicated in the
function definition and the return statement.

SRCDIR=/Users/johnsonhj/Dashboard/src/ITK #My local SRC
BLDDIR=/Users/johnsonhj/Dashboard/src/ITK-clangtidy/ #My local BLD

cd /Users/johnsonhj/Dashboard/src/ITK-clangtidy/
run-clang-tidy.py -checks=-*,modernize-return-braced-init-list  -header-filter=.* -fix

PERF: Allow compiler to choose best way to construct a copy

With move semantics added to the language and the standard library updated with
move constructors added for many types it is now interesting to take an
argument directly by value, instead of by const-reference, and then copy. This
check allows the compiler to take care of choosing the best way to construct
the copy.

The transformation is usually beneficial when the calling code passes an rvalue
and assumes the move construction is a cheap operation. This short example
illustrates how the construction of the value happens:

class Foo {
 public:
-  Foo(const std::string &Copied, const std::string &ReadOnly)
-    : Copied(Copied), ReadOnly(ReadOnly) {}
+  Foo(std::string Moved, const std::string &ReadOnly)
+    : Copied(std::move(Moved)), ReadOnly(ReadOnly) {}
 private:
   private:
   std::string Copied;
   const std::string &ReadOnly;
};

SRCDIR=/Users/johnsonhj/Dashboard/src/ITK #My local SRC
BLDDIR=/Users/johnsonhj/Dashboard/src/ITK-clangtidy/ #My local BLD

cd /Users/johnsonhj/Dashboard/src/ITK-clangtidy/
run-clang-tidy.py -checks=-*,modernize-pass-by-value  -header-filter=.* -fix

STYLE: Use range-based loops from C++11

Used as a more readable equivalent to the traditional for loop operating
over a range of values, such as all elements in a container, in the
forward direction.

====
Range based loopes are more explicit for only computing the
end location once for containers.

for ( ImageIORegion::IndexType::const_iterator i = this->GetIndex().begin();
  i != this->GetIndex().end(); //<- NOTE: Compute end every loop iteration
  ++i )

for (long i : this->GetIndex()) //<- NOTE: Implicitly only compute end once

====
Explicitly reduce the amount of index computations: (The compiler
probably does this too)

for(int i = 0; i < 11; i++)
  {
  pos[0] = testPoints[i][0];
  pos[1] = testPoints[i][1];
                    ^^^^

for(auto & testPoint : testPoints)
  {
  pos[0] = testPoint[0];
  pos[1] = testPoint[1];

====

SRCDIR=/Users/johnsonhj/Dashboard/src/ITK #My local SRC
BLDDIR=/Users/johnsonhj/Dashboard/src/ITK-clangtidy/ #My local BLD

cd /Users/johnsonhj/Dashboard/src/ITK-clangtidy/
run-clang-tidy.py -checks=-*,modernize-loop-convert  -header-filter=.* -fix

Author: hjmjohnson

include/itkArrivalFunctionToPathFilter.hxx

@@ -109,7 +109,7 @@ typename ArrivalFunctionToPathFilter<TInputImage,TOutputPath>::InputImageType *
 ArrivalFunctionToPathFilter<TInputImage,TOutputPath>
 ::ComputeArrivalFunction()
 {
-  InputImageType * function = (InputImageType *)this->ProcessObject::GetInput(0);
+  auto * function = (InputImageType *)this->ProcessObject::GetInput(0);
   return function;
 }
 

include/itkSpeedFunctionToPathFilter.hxx

@@ -106,7 +106,7 @@ SpeedFunctionToPathFilter<TInputImage,TOutputPath>
   typename NodeContainer::Pointer targets = NodeContainer::New();
   targets->Initialize();
 
-  for (typename PointsContainerType::iterator it = PrevFront.begin(); it != PrevFront.end(); it++)
+  for (auto it = PrevFront.begin(); it != PrevFront.end(); it++)
     {
       IndexType indexTargetPrevious;
       NodeType nodeTargetPrevious;
@@ -117,7 +117,7 @@ SpeedFunctionToPathFilter<TInputImage,TOutputPath>
       PrevIndexVec.push_back(indexTargetPrevious);
     }
 
-  for (typename PointsContainerType::iterator it = NextFront.begin(); it != NextFront.end(); it++)
+  for (auto it = NextFront.begin(); it != NextFront.end(); it++)
     {
       IndexType indexTargetNext;
       NodeType nodeTargetNext;
@@ -134,7 +134,7 @@ SpeedFunctionToPathFilter<TInputImage,TOutputPath>
   PointsContainerType CurrentFront =   m_Information[Superclass::m_CurrentOutput]->PeekCurrentFront(); //FrontAndAdvance();
   IndexTypeVec CurrentIndexVec(0);
 
-  for (typename PointsContainerType::iterator it = CurrentFront.begin(); it != CurrentFront.end(); it++)
+  for (auto it = CurrentFront.begin(); it != CurrentFront.end(); it++)
     {
       IndexType indexTrial;
       NodeType nodeTrial;
@@ -172,7 +172,7 @@ SpeedFunctionToPathFilter<TInputImage,TOutputPath>
   // optimizer will cross over them. This only matters if the seeds are extended
   if (CurrentIndexVec.size() > 1)
     {
-      for (typename IndexTypeVec::iterator vi = CurrentIndexVec.begin(); vi != CurrentIndexVec.end(); vi++)
+      for (auto vi = CurrentIndexVec.begin(); vi != CurrentIndexVec.end(); vi++)
         {
           m_CurrentArrivalFunction->SetPixel(*vi, 0);
         }

test/MinimalPathTest.h

@@ -92,8 +92,8 @@ int ReadPathFile( const char * PathFilename, typename PathFilterType::Pointer pa
             std::vector<itksys::String> parts;
             parts = itksys::SystemTools::SplitString( line.c_str(), ']' );
             unsigned int numNonNullParts = 0;
-            for (unsigned int i=0; i<parts.size(); i++)
-                if ( parts[i].length() != 0 ) numNonNullParts++;
+            for (auto & part : parts)
+                if ( part.length() != 0 ) numNonNullParts++;
             for (unsigned int i=0; i<numNonNullParts; i++)
             {
                 if ( parts[i].length() != 0 )
@@ -168,7 +168,7 @@ int ReadPathImage( const char * PathImagename, typename PathFilterType::Pointer
     info->SetEndPoint(pmap[2]);
     pmap.erase(1);
     pmap.erase(2);
-    for (typename PointMapType::iterator pmit = pmap.begin(); pmit != pmap.end(); ++pmit)
+    for (auto pmit = pmap.begin(); pmit != pmap.end(); ++pmit)
       {
 	info->AddWayPoint(pmit->second);
       }