variant

Related to JAXB: How to implement a JAXB-compatible variant wrapper class? , I tried to use JAXBElement to represent "variant" or "any-type". Marshalling went fine, but during Unmarshalling, JAXB tries to assign ElementNSImpl to a JAXBElement field. Test Code (copy+paste+run) import static java.lang.System.*; import java.io.*; import java.util.*; import javax.xml.bind.*; import javax.xml.bind.annotation.*; import javax.xml.namespace.*; import org.junit.*; public class _JaxbElementProblem { @XmlRootElement @XmlType @XmlAccessorType(XmlAccessType.NONE) static class MyObject { public static final

boost::variant seems a powerful container to manipulate a heterogeneous set of types. I am wondering its cost. In memory, I think it takes up the size of the largest type plus an integer representing which(). For apply_visitor(), I think its performance is very good, it can call directly the function other than lots of ifs. Are my points right? o11c You're almost right. The size of boost::variant is is the max size of any element, rounded up as needed for the largest alignment , plus the size of some integer, and again rounded up. Think about a variant of these types, assuming the tag is

I have two Delphi7 programs: a COM automation server (EXE) and the other program which is using the automation server. I need to pass an array of bytes from one program to the other. After some searching I've found that using variant arrays is the way to go (correct me please if you know any better methods). My question is: How do I create a variant array in one program, and then how do I read its values in the other? I know about VarArrayCreate and VarArrayLowBound/VarArrayHighBound, but I'm unsure on how to do this properly. Thanks! Runner You create it like that: Declarations first var

The following code: variant<string> x = "abc"; cout << get<string>(x) << "\n"; works fine under g++ (version 7.2). However, when compiled under clang++ (version 5.0) using libstdc++, I get the following error in the get method: /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/7.2.0/../../../../include/c++/7.2.0/variant:238:46: fatal error: cannot cast 'std::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >' to its private base class 'std::__detail::__variant::_Variant_storage<false, std:: __cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>

I am calling a COM object method that returns an array variant object of type 8209 in my PHP code. $com_VArray = $com_Object->objectMethod; //Is a 8209 variant object I want in the end to pass the converted VT_VARIANT object as a value for another COM object method which requires its input to be VT_VARIANT[12]. I am converting $com_VArray to a VT_VARIANT object variant type by issuing the following $obj_VT_VARIANT = variant_cast($com_VArray, VT_VARIANT); But then I get this following error Fatal error: Uncaught exception 'com_exception' with message 'Variant type conversion failed: Type

Under mac os x I have office 2011 and its excel and VBA, and I have gcc-5.3.0's g++. I played a lot to passing arrays (of numerical built-in types) from VBA to the dylib (extension of dll's on mac os x) and updating them and sending them back to VBA, see for instance : passing c/c++ dylib function taking pointer to VBA on mac Now, I would like to do the same with strings, and first with just one string, not an array. I want to receive the string from VBA, modify it in C++, and send it back, updated, to VBA. The code on the C++ side is : #include <stdlib.h> #include <ctype.h> //for toupper