Skip to main content

Unions and Constructors

You can define an union having constructors but a member of class type having constructor is not allowed in union. The reason is obvious: how would the compiler know which destructor to invoke when an object of the union goes out of scope? (for that matter, compiler does not even know which constructor to invoke at the time of creation of an object of such union)

Comments

Exciting blog. The site out did itself and will be
back! I love surfing the internet for blogs that are
exactly like this blog.
Go and find my coupon codes 1800contacts blog.
Unusual blog. I liked the site its from so much I
have to visit it again! I surf the web for blogs like
yours in my spare time.
Please take a journey to my 1800contacts com coupon blog.
dat-girl said…
Exciting blog. Your site was amazing and will be
back again! I never get tired of looking for blogs
just like this one.
You got me! I will check out your 1800contacts coupon codes blog a.s.a.p!
Creative blog. I just kept looking at it over and
over! Im always looking for blogs like this!
Go by and hit my 1800contacts coupon code blog, you'll be glad you did.
Exciting blog. Your site was amazing and will be
back again! I never get tired of looking for blogs
just like this one.
No matter when you are, just stop by and check for my 1800contacts coupon codes blog site.
stunned said…
Prodigious blog. Loved it so much I went to it
again! Just go online and search for blogs that are
worth the value as yours.
Please proceed to my coupon codes 1800contacts blog when you find the time.
Super blog. I enjoyed the site and when I have the
time, shall visit the site again. Finding blogs this
good on the internet.
You must peep out my coupon 1800contacts blog.
Super blog. I enjoyed the site and when I have the
time, shall visit the site again. Finding blogs this
good on the internet.
If your look to uncover information, please visit my 1800contacts coupon blog
Irresistible blog. I look for blogs like this one
when time allows me to. I enjoyed the site and I'll
check it next time!
You must peep out my 1800contacts coupon codes blog.
Fine blog. I found your site suitable for another
visit! And when I'm able to surf the web, I look for
blogs as great as your work.
Sweetie, go and search my plastic surgery for man blog for what you need.
Anonymous said…
Super blog. I enjoyed the site and when I have the
time, shall visit the site again. Finding blogs this
good on the internet.
gclub

Popular Content

Multi-dimensional arrays in C++11

What new can be said about multi-dimensional arrays in C++? As it turns out, quite a bit! With the advent of C++11, we get new standard library class std::array. We also get new language features, such as template aliases and variadic templates. So I'll talk about interesting ways in which they come together. It all started with a simple question of how to define a multi-dimensional std::array. It is a great example of deceptively simple things. Are the following the two arrays identical except that one is native and the other one is std::array? int native[3][4]; std::array<std::array<int, 3>, 4> arr; No! They are not. In fact, arr is more like an int[4][3]. Note the difference in the array subscripts. The native array is an array of 3 elements where every element is itself an array of 4 integers. 3 rows and 4 columns. If you want a std::array with the same layout, what you really need is: std::array<std::array<int, 4>, 3> arr; That's quite annoying for

Unit Testing C++ Templates and Mock Injection Using Traits

Unit testing your template code comes up from time to time. (You test your templates, right?) Some templates are easy to test. No others. Sometimes it's not clear how to about injecting mock code into the template code that's under test. I've seen several reasons why code injection becomes challenging. Here I've outlined some examples below with roughly increasing code injection difficulty. Template accepts a type argument and an object of the same type by reference in constructor Template accepts a type argument. Makes a copy of the constructor argument or simply does not take one Template accepts a type argument and instantiates multiple interrelated templates without virtual functions Lets start with the easy ones. Template accepts a type argument and an object of the same type by reference in constructor This one appears straight-forward because the unit test simply instantiates the template under test with a mock type. Some assertion might be tested in

Want speed? Use constexpr meta-programming!

It's official: C++11 has two meta-programming languages embedded in it! One is based on templates and other one using constexpr . Templates have been extensively used for meta-programming in C++03. C++11 now gives you one more option of writing compile-time meta-programs using constexpr . The capabilities differ, however. The meta-programming language that uses templates was discovered accidently and since then countless techniques have been developed. It is a pure functional language which allows you to manipulate compile-time integral literals and types but not floating point literals. Most people find the syntax of template meta-programming quite abominable because meta-functions must be implemented as structures and nested typedefs. Compile-time performance is also a pain point for this language feature. The generalized constant expressions (constexpr for short) feature allows C++11 compiler to peek into the implementation of a function (even classes) and perform optimization