When you declare something as extern, that tells the compiler, don't worry about it, it is defined somewhere else, let linker to take care of it. Here is a simple example. //main.cpp #include <iostream> using namespace std; int main(){ extern int x; extern int foo(int y); cout << x << endl; cout << foo(10) << endl; return 0; } //x.cpp int x=5; int foo(int y){ y += x; return y; }

C++ is a superset of something, we're not sure what. You can use a C++ compiler to compile C code, but the results may surprise you. See similar questions...

You sure can. There really are two ways. You can use it directly, or through one of the C++ wrappers for Motif. Much of this is discussed in the Motif FAQ which can be found at Ken Lee's website at http://www.rahul.net/~kenton Using LessTif directly with C++ prompts the question on how to use class member functions as callbacks. See similar questions...

It refers to a variable which is not actually in your program. For instance, main() { extern int bar; printf("%d\n", bar); return 0; } will compile without errors because bar is declared as being external. (It won't run, though, because you never assign bar a value.) [a] See similar questions...

You need to manually edit /waffle/menus/editors to reflect the editors that are available on your system. Make sure to include a separate entry so that the user can select 'none' to get back to the internal editor. See similar questions...

No, C# has no direct equivalent of the C++ typedef. C# does allow an alias to be specified via the using keyword: using IntList = System.Collections.Generic.List<int>; but the alias only applies in the file in which it is declared. A workaround in some cases is to use inheritance: public class IntList : List<int> { } See similar questions...

Yes, in fact exceptions are the recommended error-handling mechanism in C# (and in .NET in general). Most of the .NET framework classes use exceptions to signal errors. See similar questions...

No, you should not use a rechargeable battery with your Seiko Cleancut and here's why. The speed of any DC motor is directly related to the voltage of the power supply; the higher the voltage the faster the motor turns. By their nature rechargeable batteries do not have as high a voltage as alkaline batteries. For instance a fresh alkaline "C" cell, which is a 1.5 volt battery, will test out as high as 1.6 volts right out of the package. See similar questions...

Yes. First of all, since you can call C functions from C++ you can access all the DCE services from a C++ program. But that will not give you the benefits of C++. There are several packages that provide a C++ interface to DCE. They different quite a bit in style and approach, so you'll need to consider them carefully in light of your own needs and preferences. Objtran was produced by Citibank, and is available by anonymous ftp at ftp://wilma.cs.brown.edu/pub/Objtran.tar. See similar questions...

You need to place the explosives into a cabinet which is located somewhere in the middle of the bridge, between some barrels. Examine the cabinet and drag the explosives in there. See similar questions...

MATLAB's MEX-file facility allows user to use C and Fortran subroutines as MATLAB m-files. It is also possible to use MATLAB as a computational engine for C/Fortran subroutines. See similar questions...

C# is a new language designed by Microsoft to work with the .NET framework. In their "Introduction to C#" whitepaper, Microsoft describe C# as follows: C# is a simple, modern, object oriented, and type-safe programming language derived from C and C++. C# (pronounced "C sharp") is firmly planted in the C and C++ family tree of languages, and will immediately be familiar to C and C++ programmers. C# aims to combine the high productivity of Visual Basic and the raw power of C++. See similar questions...

This is a very subjective question. Different people like different things so there's no right or wrong answer. Since this question is asked QUITE frequently, I will link to the most recent occasion on which it was asked and answered by a number of people. See similar questions...

Beside searching for binding sites in DNA sequence, TESS also let's you query TRANSFAC directly. These capabilities are accessible through the Query Transfac and Query Matrices links at the top of every page. You may want to preview which factors match c-Jun. Do this by selecting 'Accession Numbers' from the popup menu in the Results section. To select a few factor entries of interest, select 'Accession Number' in the 'Search in this field' popup menu and enter, for example, T00131|T00133. See similar questions...

A#6.2: === See the CAVEAT in Q#6.1 === There are a few aspects to this, so it has been split into various questions in this section of the FAQ. You should read each of those questions when so directed, below. The following instructions assume that you have already installed your ORCA languages; various files and directories will be moved from their original locations. If you haven't already done so, change the auxtype of (original_orca_directory)/shell/Editor to hex DC00 (see Q#14.1). See similar questions...

Yes. This is the method we recommend to our customers who require high-performance web applications. A minimal FastCGI program in C would look like: #include "fcgi_stdio.h" #include <stdlib.h> int main(int argc, char *argv) { int count = 0; while (FCGI_Accept() >= 0) { printf("Content-type: text/html\r\n\r\n" "Request: %d on host %s", count++, getenv("SERVER_NAME")); } return (0); } See similar questions...

Change the file extention to cpp first; compile it under g++ or other c++ compiler; fix all the possible compiling errors, mostly, type checking errors, since c++ check type more strictly. If you are lucky, maybe none. Dealing with individual c-functions, you can use the following compiling directives to make your header file be used by both c and c++. #ifdef __cplusplus extern "C" { #endif // list all your c functions here #ifdef __cplusplus } #endif You are in c++ now. See similar questions...

Yes, these two companion products were formulated to work synergistically. This will give you the best possible results in the shortest period of time. See similar questions...

C# supports a very similar range of basic types to C++, including int, long, float, double, char, string, arrays, structs and classes. However, don't assume too much. The names may be familiar, but many of the details are different. For example, a long is 64 bits in C#, whereas in C++ the size of a long depends on the platform (typically 32 bits on a 32-bit platform, 64 bits on a 64-bit platform). Also classes and structs are almost the same in C++ - this is not true for C#. See similar questions...