olibre

C++ : Polymorphic inheritance without vtable

Inheritance and Virtual Table are often used to create interface in C++ polymorphic class
What if ... there were another way to do this ?
easier, cleaner, faster and more reliable
This article explains how to use CRTP, [std::variant](https://en.cppreference.com/w/cpp/utility/variant and std::visit to increase code performance.

Table of content

1. Introduction

SubCoder1

#include <bits/stdc++.h>
 using namespace std;

struct node {
    int data{};
    node* left = nullptr;
    node* right = nullptr;
    node* parent = nullptr;
    string color;
};

HertzDevil

#pragma once

#include <type_traits>
#include <limits>

// The default enumeration category. Conversion is equivalent to static_cast.
// Unspecialized enumeration traits use this category.
struct enum_default { };

// The standard-layout enumeration category. Values outside the given range are

hatarist

SELECT
  *,
  pg_size_pretty(table_bytes) AS table,
  pg_size_pretty(index_bytes) AS index,
  pg_size_pretty(total_bytes) AS total
FROM (
  SELECT
    *, total_bytes - index_bytes - COALESCE(toast_bytes, 0) AS table_bytes
  FROM (
    SELECT

jdtournier

A short demo showing the explicit instantiation of templates, and how to avoid parsing the full definition(s) in every compilation unit. The limitation is that it will only be possible to use the specific specialisations explicitly instantiated in the cpp file.

yydai

/***
 * Excerpted from "The Definitive ANTLR 4 Reference",
 * published by The Pragmatic Bookshelf.
 * Copyrights apply to this code. It may not be used to create training material, 
 * courses, books, articles, and the like. Contact us if you are in doubt.
 * We make no guarantees that this code is fit for any purpose. 
 * Visit http://www.pragmaticprogrammer.com/titles/tpantlr2 for more book information.
***/
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.tree.ParseTree;

oinopion

-- Create a group
CREATE ROLE readaccess;

-- Grant access to existing tables
GRANT USAGE ON SCHEMA public TO readaccess;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readaccess;

-- Grant access to future tables
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readaccess;

jdegoes

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

derofim

About

C++ code style written in markdown.

Auto code formatting tool

Astyle code automatic formatting settings
You can use clang-format too.

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Use tools like vera++

pathikrit

/**
 * Solves the n-Queen puzzle in O(n!)
 * Let p[r] be the column of the queen on the rth row (must be exactly 1 queen per row)
 * There also must be exactly 1 queen per column and hence p must be a permuation of (0 until n)
 * There must be n distinct (col + diag) and n distinct (col - diag) for each queen (else bishop attacks)
 * @return returns a Iterator of solutions 
 *     Each solution is an array p of length n such that p[i] is the column of the queen on the ith row
 */
def nQueens(n: Int): Iterator[Seq[Int]] = 
  (0 until n)