Re: [eigen] Overloading componentwise binary operators for vectors

[Cedric Doucet <cedric.doucet@xxxxxxxx>]

 If needed, here is the CMake configuration script for the small example.

You just have to adapt the following line with eigen installation path:

include_directories(eigen/install/include/eigen3)

---

De: "Gael Guennebaud" <gael.guennebaud@xxxxxxxxx>
À: "eigen" <eigen@xxxxxxxxxxxxxxxxxxx>
Envoyé: Samedi 3 Octobre 2015 00:10:05
Objet: Re: [eigen] Overloading componentwise binary operators for vectors

On Fri, Oct 2, 2015 at 10:25 PM, Cedric Doucet <cedric.doucet@xxxxxxxx> wrote:

========================================================

template<typename ScalarType>

Vector<ScalarType> operator+(Vector<ScalarType> const & lhs, Vector<ScalarType> const & rhs)

{ return lhs.wrapped_ + right.wrapped_; }

========================================================

does not work. I guess it is because an _expression_ template is returned by operator + in Eigen.

This should work if your Vector class has a template constructor from an Eigen::DenseBase<Derived>. Of course, this way you will loose the benefits of Eigen's _expression_ templates.

========================================================
erreur: ambiguous overload for ‘operator+’ (operand types are ‘Vector<double>’ and ‘Vector<double>’)
CPPUNIT_ASSERT_EQUAL(sum, left+right);
========================================================

Please show what are the multiple versions of operator+ found by the compiler.

Anyways, instead of writing a wrapper, maybe extending MatrixBase<> to add compatibility methods or inherit Matrix<> could work for you? See:

http://eigen.tuxfamily.org/dox-devel/TopicCustomizingEigen.html

gael

cmake_minimum_required (VERSION 2.6)

project (eigen_overloading CXX)

#==============
# INCLUDE FILES
#==============

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)

include(CheckCXXCompilerFlag)
include(ProcessorCount)

ProcessorCount(N)
if(NOT N EQUAL 0)
  set(CMAKE_BUILD_FLAGS -j${N})
endif()
#====================
# EXECUTABLE SETTINGS
#====================
add_executable(main main.cpp)

#=============
# USER OPTIONS
#=============


#=============================
# DOWNLOAD 3RD-PARTY LIBRARIES
#=============================


  include_directories(eigen/install/include/eigen3)

#==================
# COMPILER SETTINGS
#==================

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SIMOL_CXX_FLAGS} -Wall -Wextra")

CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
if(COMPILER_SUPPORTS_CXX11)
	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
else()
  message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} does not support -std=c++11 flag. Please use a different C++ compiler.")
endif()