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Subject: Re: [boost] [countertree] Formal Review Request
From: Francisco José Tapia (fjtapia_at_[hidden])
Date: 2012-10-05 12:47:53

Hi Mr Simonson.

About the utility of vector_tree.

Some years ago I worked in a atomic simulation of silicon doping for the
semiconductor design. The silicon to high temperature produce spontaneous
“defects” in the atomic structure of the silicon. This depend of the
temperature, and the probability of the kind of “defect”. The "defects"
makes the silicon semiconductor

 Each time interval we throw a buch of electrons with high energy against
the silicon. When the electron crash with the defect, depending of the
energy of the electron , and the angle, can occur several things. The
defect absorb the electron, , the electron break the defect and generate
new defects, others rebound and in others destroy the defect. The positions
are continuously changing.

 You can't sort by any parameter. I had the defects in a vector_tree, and
divide the number of defects between the number or cores of the machine,
assign to each core their defects and begin to process. The possibility of
insert and delete in any position at log(N), was very useful. As you can
imagine, the complexity was bigger than the described here, but I thing
this is not place for to show a detailed specification of the project.

 The word is bigger than I had seen, even bigger than I can imagine. And
every day I learn and expect new things for to be astonished. It is the
same since 28 years ago, when I began to program in C, and 22 years ago
when I began to program in C++ ( I bought the TurboC++ 1.0 in 1990, 1 week
after it appear in the market ).

About the standard:

 The history shows than the facts change the rules. According to the
standard, to use std::sort and binary search over a vector_tree is wrong.
But it run well, and the time spent in sort a million elements is similar
to insert the elements in a std::set.

 I don't question the standard. I only show the facts. It run well, and,
the most important for me, I thing it can be useful to the programmers
community. This is my motivation for to do this.

The standard can be expanded, relaxed, modified or nothing. What do you
suggest me ? Delete the library, because it is not according to the
standard, or perhaps , think about what need to be changed, or modified in
the standard for to adapt to the new reality.

  The new C++11 appear when the library was finished, and I was writing the
documentation and checking the code. The new standard is very good, but
have a problem, if you do according the last standard , you are discarding
the majority of the C++ compilers used actually.

My idea is to use the new features of C++11, but trying to maintain the
compatibility with older compilers, at least until the new standard was

 About the statefull allocators. I have my own idea, but I need to study
more in order to have a founded opinion. The suballocator can be
transformed in statefull allocators with a few changes in the actual code,
but I need to think about the utility and the problems related.


 Francisco Tapia

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