c++

[Solved] SelectMany Linq [closed]

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[ad_1] Check the reference source from Microsoft here Following is the SelectMany overload being utilized public static IEnumerable<TResult> SelectMany<TSource, TCollection, TResult>(this IEnumerable<TSource> source, Func<TSource, IEnumerable<TCollection>> collectionSelector, Func<TSource, TCollection, TResult> resultSelector) { if (source == null) throw Error.ArgumentNull(“source”); if (collectionSelector == null) throw Error.ArgumentNull(“collectionSelector”); if (resultSelector == null) throw Error.ArgumentNull(“resultSelector”); return SelectManyIterator<TSource, TCollection, TResult>(source, collectionSelector, resultSelector); … Read more

[Solved] Difference between Exception(String) and Exception(String,Exception) [closed]

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[ad_1] The difference is: The Exception(String, Exception) constructor creates an Exception with an InnerException (Exception) and a message (String) The Exception(String) constructor create an Exception with only a message (String) and the InnerException is NULL You can check this information here.https://msdn.microsoft.com/en-us/library/system.exception.exception(v=vs.110).aspx Hope this helps. [ad_2] solved Difference between Exception(String) and Exception(String,Exception) [closed]

[Solved] Do I need to do a free on a struct? [closed]

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[ad_1] you shall not free() instances that have not been allocated through malloc(), though it’s unclear how the instance has been allocated before being given to that function, though it’s unlikely it’s been malloc()ed as this is C++, which leads me to 2. ; you should not free() C++ objects, but instead call delete that … Read more

[Solved] C printf cross-platform format without warnings [duplicate]

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[ad_1] For size_t, assuming you have a sufficiently modern C library, use %zu. If you can’t use the z modifier (some older libraries unfortunately don’t support it), cast to a wide-enough known type when printing, and then use a width specifier appropriate to that type: size_t sz = sizeof(whatever); … printf(“%lu”, (unsigned long)sz); This works … Read more

[Solved] C++ errors for C code

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[ad_1] First of all, you need to decide whether you’re writing C or C++. C does not support classes, and you should not use C-style strings, I/O, and memory management routines in C++ code. Mixing elements of the two languages is a recipe for heartburn. C and C++ are completely different languages that happen to … Read more

[Solved] My codes work well In Dev c++ IDE, but in linux terminal, it doesn’t. (especially in the part of ‘while’ loop.) [closed]

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[ad_1] You are most likely running into the NL/CR issue. Instead of if (a[i]==””) Use something like: if (isEmptyLine(a[i])) where bool isEmptyLine(std::string const& s) { for ( auto c : s ) { if ( !std::isspace(c) ) return false; } return true; } You can also convert the file into a file with UNIX style … Read more

[Solved] Very disturbing error message

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[ad_1] MyObject->MyFunc, as the error says, cannot be used for anything except an immediate function call. You can’t even take its sizeof, even if some compilers allow that. I think what you mean is sizeof(&ClassName::FunctionName). That’s simpler, will actually compile, and doesn’t invoke undefined behavior (dereferencing a null pointer is UB, even if you don’t … Read more

[Solved] Operator in C/C++ [closed]

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[ad_1] In this expression (b,a) there is the comma operator. Its value is the value of the last (right) subexpression after the comma. The value of the first (left) subexpression is discarded. So the output will be 6 From the C++ Standard A pair of expressions separated by a comma is evaluated left-to-right; the left … Read more