xealits

#!/usr/bin/env python
import ctypes
from ctypes import cdll

cur_x = 10
libpath = "./some_lib.so"
lib = cdll.LoadLibrary(libpath)
print(f"loaded {lib}")

# https://stackoverflow.com/a/62021495/1420489

xealits

#include <iostream>

struct FuncPtr;
typedef FuncPtr(Func)(int);

struct FuncPtr {
  void *func;
  FuncPtr(Func& f) : func{(void *) &f} {};
  FuncPtr operator()(int x) { return ((Func *)func)(x); }
};

xealits

# 1 "<built-in>"
# 1 "specialise_variadic_templates.cpp"
#if defined(__CLANG_REWRITTEN_INCLUDES) || defined(__CLANG_REWRITTEN_SYSTEM_INCLUDES) /* iostream expanded by -frewrite-includes */
#include <iostream>
#else /* iostream expanded by -frewrite-includes */
# 1 "specialise_variadic_templates.cpp"
# 1 "/usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/iostream" 1 3
// Standard iostream objects -*- C++ -*-

xealits

#include <iostream>
#include <source_location>
#include <string>

struct Quack;
template <typename T>
concept Duck = requires(T t) {
  { t.quack() } -> std::convertible_to<Quack>;
  //   could be -> std::same_as<Quack>;
};

xealits

Find references to non-const pointees:

clang-query -c "set output dump" -c "m varDecl(hasType(referenceType(pointee(unless(isConstQualified())))))" source.cpp

xealits

/*
 * Just some notes while reading Game Programming Patterns by Robert Nystrom
 * https://gameprogrammingpatterns.com
 *
 * A command or event made with C++ std::variant.
 * The idea is to pack some similar-size but different types into the command.
 * How to subscribe components to events from each other
 * and construct it declaratively, at compile time?
 * The components send events or commands (command pattern).
 * You want to verify the interfaces, preferably statically, i.e. at link time.

xealits

#[
# the example is from https://peterme.net/metaprogramming-and-read-and-maintainability-in-nim.html
# plus I used `quote` instead of direct tree nodes
# it almost works the same way
# except, it seems you cannot declare an empty `enum` under `quote`
]#

import math, strutils
import macros

xealits

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• I am xealits on github.
• I am alex_toldaiev (https://keybase.io/alex_toldaiev) on keybase.
• I have a public key ASCzSvsKrscH62AXDRlMSAWr_qCTE-c4i6EUDECNisX1pgo

To claim this, I am signing this object:

xealits

#define DOCTEST_CONFIG_IMPLEMENTATION_IN_DLL
#include "doctest.h"

//int factorial(int number) { return number <= 1 ? number : factorial(number - 1) * number; }
int factorial(int number) { return number <= 1 ? 1 : factorial(number - 1) * number; }

TEST_CASE("testing the factorial function") {
    CHECK(factorial(0) == 1);
    CHECK(factorial(1) == 1);
    CHECK(factorial(2) == 2);

xealits

What exactly is "iowait"?

To summarize it in one sentence, 'iowait' is the percentage
of time the CPU is idle AND there is at least one I/O
in progress.

Each CPU can be in one of four states: user, sys, idle, iowait.
Performance tools such as vmstat, iostat, sar, etc. print
out these four states as a percentage.  The sar tool can
print out the states on a per CPU basis (-P flag) but most