Tl;dr

In some cases, the newly introduced std::string_view in C++17 is faster than std::string, because string_view only needs the pointer to the first element and the length of the string sequence, it omits string copy and provides an immutable-view of original data.

A copy constructor of class T is a non-template constructor whose first parameter is T&‍, const T&‍, volatile T&‍, or const volatile T&‍, and either there are no other parameters, or the rest of the parameters all have default values.

from cppreference.com

Syntax

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// Typical declaration of a copy constructor.
class_name ( const class_name & )
// Forcing a copy constructor to be generated by the compiler.
class_name ( const class_name & ) = default;
// Avoiding implicit generation of the copy constructor.
class_name ( const class_name & ) = delete;

In C++ computer programming, copy elision refers to a compiler optimization technique that eliminates unnecessary copying of objects.
…
Return value optimization (RVO) is a compiler optimization that involves eliminating the temporary object created to hold a function’s return value.

from Wikipedia

2017 年的尾巴，趁着刚刚入职又赶上了圣诞和新年假期，我们计划了一段十天左右的自驾游行程，算是对经历了各种考验的 2017 的一次正式告别！

这段旅程，绝对是这辈子独一无二的精彩回忆！

我们的自驾游行程基本如下图所示，五大国家公园串成一条环线，从 Vegas 出发，再回到 Vegas 跨年。这中间会依次经过 Zion，Bryce，Arches，Canyonlands，Grand Canyon，Monument Valley，Antelope Canyon 以及 Valley of Fire。

The iputils package is set of small useful utilities for Linux networking. when I tried to compile it from CentOS 7, it turned out to be lacking some dependencies by default.

Top K frequent elements is a classic interview question that requires a basic understanding of HashMap and Heap. In this post, we will start with a leetcode question to see how to use HashMap and sorting to solve this problem in a single machine. After that we will dig deep into a system design question if we want top k frequent elements from a data stream, the second problem can also be referred as Heavy Hitters.