Skip to main content

Visual C++ ... MD and MT compile option

This article is only for limited audiences. If you use Visual Studio C++ (2008) and have a question about What is the MD and MT, then you might be interested in this.

When I made a Console Application on the Visual C++ 2008 using STL. I start to get the following error.

error LNK2001: unresolved external symbol __imp___CrtDbgReportW

It is related with a Windows runtime library. One thing is Unicode related, so I switched off.

It seems this is related C/C++ Code generation, Multi-threaded Debug Dll (MT option) (/Mdd) or Multi-threaded debug (/MTd). (Note: only one character difference /MDd and /MTd.) In some reason while I develop an application, I got a warning about there is a library conflict, and suggested to ignore one of the runtime libraries. I followed the link's output and ignore the 'MSVCRT' library. But this is the problem. I removed it from the ignore library list.

I set up all the Code Generation to Multi-threaded Debug DLL (/MDd) for debug, and not ignore any runtime library. Then now it works. This was a confusion.

Then, I asked my colleague, T. What is this MD and MT stuffs. He said:

- MT: Multi-threaded static library. This is good for distribution a whole application package, since everything is statically linked and there is no dependency to the environment.

- MD: Multi-threaded Dynamic link library. If you distribute some library instead of a whole application, dynamically linked runtime is better since, some part of the program uses one version of runtime, and the other uses different version,this causes a trouble. For example, 'new'ed some memory at one version of runtime, and 'delete'd by other version of runtime could be a trouble.

So, it depends on the situation and I see now it is better to have both. But these are too similar and I am easy to confuse them.

Comments

Popular posts from this blog

Why A^{T}A is invertible? (2) Linear Algebra

Why A^{T}A has the inverse Let me explain why A^{T}A has the inverse, if the columns of A are independent. First, if a matrix is n by n, and all the columns are independent, then this is a square full rank matrix. Therefore, there is the inverse. So, the problem is when A is a m by n, rectangle matrix.  Strang's explanation is based on null space. Null space and column space are the fundamental of the linear algebra. This explanation is simple and clear. However, when I was a University student, I did not recall the explanation of the null space in my linear algebra class. Maybe I was careless. I regret that... Explanation based on null space This explanation is based on Strang's book. Column space and null space are the main characters. Let's start with this explanation. Assume  x  where x is in the null space of A .  The matrices ( A^{T} A ) and A share the null space as the following: This means, if x is in the null space of A , x is also in the n...

Gauss's quote for positive, negative, and imaginary number

Recently I watched the following great videos about imaginary numbers by Welch Labs. https://youtu.be/T647CGsuOVU?list=PLiaHhY2iBX9g6KIvZ_703G3KJXapKkNaF I like this article about naming of math by Kalid Azad. https://betterexplained.com/articles/learning-tip-idea-name/ Both articles mentioned about Gauss, who suggested to use other names of positive, negative, and imaginary numbers. Gauss wrote these names are wrong and that is one of the reason people didn't get why negative times negative is positive, or, pure positive imaginary times pure positive imaginary is negative real number. I made a few videos about explaining why -1 * -1 = +1, too. Explanation: why -1 * -1 = +1 by pattern https://youtu.be/uD7JRdAzKP8 Explanation: why -1 * -1 = +1 by climbing a mountain https://youtu.be/uD7JRdAzKP8 But actually Gauss's insight is much powerful. The original is in the Gauß, Werke, Bd. 2, S. 178 . Hätte man +1, -1, √-1) nicht positiv, negative, imaginäre (oder gar um...

Why parallelogram area is |ad-bc|?

Here is my question. The area of parallelogram is the difference of these two rectangles (red rectangle - blue rectangle). This is not intuitive for me. If you also think it is not so intuitive, you might interested in my slides. I try to explain this for hight school students. Slides:  A bit intuitive (for me) explanation of area of parallelogram  (to my site, external link) .