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C++

08/14/19

How can I convert a std::string to int?

Just have a quick question. I've looked around the internet quite a bit and I've found a few solutions but none of them have worked yet. Looking at converting a string to an int and I don't mean... more

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C++

08/12/19

What is a smart pointer and when should I use one?

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Answers •1

C++

08/12/19

How do I output coloured text to a Linux terminal?

How do I print coloured characters to a Linux terminal that supports it? How do I tell whether the terminal supports colour codes?

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Answers •1

C++

08/11/19

What is the lifetime of a static variable in a C++ function?

If a variable is declared as `static` in a function's scope it is only initialized once and retains its value between function calls. What exactly is its lifetime? When do its constructor and... more

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C++

08/10/19

When you should use virtual inheritance?

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C++

08/09/19

Why does C++ compilation take so long?

Compiling a C++ file takes a very long time when compared to C# and Java. It takes significantly longer to compile a C++ file than it would to run a normal size Python script. I'm currently using... more

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C++

08/07/19

How to convert a std::string to const char* or char*?

How can I convert an `std::string` to a `char*` or a `const char*`?

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C++

08/07/19

How do malloc() and free() work?

I want to know how `malloc` and `free` work. int main() { unsigned char *p = (unsigned char*)malloc(4*sizeof(unsigned char)); memset(p,0,4); strcpy((char*)p,"abcdabcd"); //... more

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C++

08/07/19

What is external linkage and internal linkage?

I want to understand the external linkage and internal linkage and their difference. I also want to know the meaning of > `const` variables internally link by default unless otherwise... more

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C++

08/06/19

Why does the order in which libraries are linked sometimes cause errors in GCC?

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C++

08/05/19

What is the meaning of prepended double colon "::"?

I found this line of a code in a class which I have to modify: ::Configuration * tmpCo = m_configurationDB;//pointer to current db and I don't know what exactly means the double colon prepended... more

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C++

08/04/19

Advantages of using forward?

In perfect forwarding, `std::forward` is used to convert the named rvalue references `t1` and `t2` to unnamed rvalue references. What is the purpose of doing that? How would that affect the called... more

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C++

08/04/19

How to convert vector to array?

How do I convert a `std::vector<double>` to a `double array[]`?

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C++

08/03/19

Difference between static and shared libraries?

What is the difference between static and shared libraries? I use Eclipse and there are several project types including Static Libraries and Shared Libraries? Does one have an advantage over the... more

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C++

08/02/19

What are the barriers to understanding pointers and what can be done to overcome them?

Why are pointers such a leading factor of confusion for many new, and even old, college level students in C or C++? Are there any tools or thought processes that helped you understand how pointers... more

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C++

07/31/19

What is the difference between const int, const int const, and int const *?

I always mess up how to use `const int*`, `const int * const`, and `int const *` correctly. Is there a set of rules defining what you can and cannot do? I want to know all the do's and all don'ts... more

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C++

07/30/19

What is the difference between the dot (.) operator and -> in C++?

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C++

07/30/19

Why does changing 0.1f to 0 slow down performance by 10x?

Why does this bit of code, const float x[16] = { 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6}; const float z[16] = {1.123,... more

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C++

07/30/19

How do I execute a command and get output of command within C++ using POSIX?

I am looking for a way to get the output of a command when it is run from within a C++ program. I have looked at using the system() function, but that will just execute a command. Here's an example... more

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C++

07/29/19

Pointer vs. Reference?

What would be better practice when giving a function the original variable to work with: unsigned long x = 4; void func1(unsigned long& val) { val = 5; } func1(x); or: ... more

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C++

07/28/19

Initialization of a normal array with one default value?

[C++ Notes: Array Initialization](http://www.fredosaurus.com/notes-cpp/arrayptr/array-initialization.html) has a nice list over initialization of arrays. I have a int array[100] = {-1};expecting... more

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C++

07/28/19

How to check that an element is in a std::set?

How do you check that an element is in a set? Is there a simpler equivalent of the following code: myset.find(x) != myset.end()

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C++

07/27/19

When to use extern in C++?

I'm reading "Think in C++" and it just introduced the `extern` declaration. For example: extern int x; extern float y; I think I understand the meaning (declaration without definition), but... more

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C++

07/27/19

What do single quotes do in C++ when used on multiple characters?

I'm curious about this code: cout << 'test'; // Note the single quotes. gives me an output of `1952805748`. My question: Is the output an address in memory or something?

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C++

07/27/19

Why use apparently meaningless do-while and if-else statements in macros?

In many C/C++ macros I'm seeing the code of the macro wrapped in what seems like a meaningless `do while` loop. Here are examples. #define FOO(X) do { f(X); g(X); } while (0) #define FOO(X) if... more

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How can I convert a std::string to int?

What is a smart pointer and when should I use one?

How do I output coloured text to a Linux terminal?

What is the lifetime of a static variable in a C++ function?

When you should use virtual inheritance?

Why does C++ compilation take so long?

How to convert a std::string to const char* or char*?

How do malloc() and free() work?

What is external linkage and internal linkage?

Why does the order in which libraries are linked sometimes cause errors in GCC?

What is the meaning of prepended double colon "::"?

Advantages of using forward?

How to convert vector to array?

Difference between static and shared libraries?

What are the barriers to understanding pointers and what can be done to overcome them?

What is the difference between const int*, const int * const, and int const *?

What is the difference between the dot (.) operator and -> in C++?

Why does changing 0.1f to 0 slow down performance by 10x?

How do I execute a command and get output of command within C++ using POSIX?

Pointer vs. Reference?

Initialization of a normal array with one default value?

How to check that an element is in a std::set?

When to use extern in C++?

What do single quotes do in C++ when used on multiple characters?

Why use apparently meaningless do-while and if-else statements in macros?

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What is the difference between const int, const int const, and int const *?