[eigen] To initialize or not to initialize

[Adolfo Rodríguez Tsouroukdissian <adolfo.rodriguez@xxxxxxxxxxxxxxxx>]

Looking into the code of various decompositions I've seen that the constructors for input matrix are sometimes implemented like this (dummy example):

fooDecomp(const MatrixType& matrix) : m_mat(matrix.rows(), matrix.rows())
{
  compute(matrix);
}

and sometimes like this:

fooDecomp(const 
MatrixType& matrix) // <- Notice no initialization
{
  compute(matrix);
}

First of all, I'd like to propose uniforming this (I could do it), but I also wanted to know how big a difference is there between the two alternatives.
I know that in general it's best to follow the first approach and initialize class members, but is it still so in the case of Eigen matrices?. Are the differences greater when certain macros are defines, such as EIGEN_INITIALIZE_BY_ZERO_IF_THAT_OPTION_IS_ENABLED?

TIA,

Adolfo

-- 
Adolfo Rodríguez Tsouroukdissian, Ph.. D.

Robotics engineer
PAL ROBOTICS S.L
http://www.pal-robotics.com
Tel. +34.93.414.53.47
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