#tuesdaycodingtips
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Tip 96 of #tuesdaycodingtips - Reference equality in C#

Languages other than C++ are also prone to having "fun" footguns. Take C#'s reference semantics for example. All I wanted was a dictionary with a file hash as a key. Since built-in cryptographic tools […]

[Original post on techhub.social]
Short snippet showing that the same hash with a different object reference throws an exception when used as a dictionary key. Snippet showing how to write a custom comparator that can alleviate the issue.
April 21, 2026 at 10:56 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 95 of #tuesdaycodingtips - Copy & swap idiom

Rule of 5 says that if you need to implement one of the copy/move constructors/assignment operators or a destructor, you shall implement all of them to avoid resource management issues. However, this often […]

[Original post on techhub.social]
Class with naive implementation of rule of 5. Rule of 5 where assignment operators don't duplicate logic with copy and move constructors. Rule of 5, where both assignment operators were squashed into one.
March 24, 2026 at 11:22 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 94 of hashtag#TuesdayCodingTips - C# Disposable pattern

Disposable pattern is an attempt to retrofit scope-based resource management into a garbage-collected language. It executes a dedicated cleanup function when the object goes out of scope, rather than […]

[Original post on techhub.social]
C# code showing Disposable pattern implementation for sealed class with no managed resources. C# code showing Disposable pattern implementation for a sealed class with managed resources. C# code showing Disposable pattern implementation for base/derived class combo.
March 10, 2026 at 11:08 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 93 of #tuesdaycodingtips - Constrained auto

Tired of convoluted templates in your C++? Want to make them more legible?

C++20 introduced concepts - a powerful feature that can restrict your templated APIs to only such arguments that fulfil a particular […]

[Original post on techhub.social]
C++ source code showing how constrained auto can simplify code.
February 24, 2026 at 11:16 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 92 of #tuesdaycodingtips - Pinning interop memory in C#

When interoping C# with, for example, C++, one can send a pointer to the managed memory directly to the native code and work with it without the need to copy it into the local address space. For as […]

[Original post on techhub.social]
C# snippet showing how to pin a byte array in c# before passing it to native code.
September 23, 2025 at 10:40 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 91 of #tuesdaycodingtips - String or StringBuilder?

If you're a C++ programmer, you can easily troll yourself while working with C#'s `string` objects. In C++, they are optimized vectors of bytes and can be dynamically resized at will through […]

[Original post on techhub.social]
C# code snippet that demonstrates immutability of strings and performance hits of using a string vs StringBuilder.
September 2, 2025 at 1:53 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 90 of #tuesdaycodingtips - Is enum value defined?

In both C++ and C#, enums are mere named numerical constants. Even if they appear to be distinct types, and switch statements can check whether you covered all names within an enum, that's simply not […]

[Original post on techhub.social]
C# code snippet showcasing Enum.IsDefined usage.
August 19, 2025 at 1:25 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 89 of #tuesdaycodingtips - Semantic versioning

When creating a library, semantic versioning is a really useful versioning scheme to use.

It's a promise to your users that changes bumping the minor/patch version numbers are backward-compatible. As such, much of the software relies on these […]
Original post on techhub.social
techhub.social
July 8, 2025 at 12:59 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 88 of #tuesdaycodingtips - Enum-discriminated unions with nlohmann::json

JSON is a fairly trivial format and as such, its only way of supporting polymorphic data is an enum-discriminated approach.

In other words, you might have an array of objects where […]

[Original post on techhub.social]
A C++ code snippet which shows json (de)serialization of a vector of variants with overloaded adl_serializer and nlohmann::json.
June 24, 2025 at 10:14 AM
jakub-neruda.techhub.social.ap.brid.gy
They say learning by example is the best way to learn. I'd like to share one such example of API design process based on a recent discussion with one of my colleagues: https://medium.com/@nerudaj/a-case-study-on-api-design-f22a8665cf2d

If you follow my #tuesdaycodingtips, this showcases a […]
Original post on techhub.social
techhub.social
June 12, 2025 at 11:06 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 87 of #tuesdaycodingtips - Emplace into a vector of variants

`emplace_*` is an alternative to methods like `insert` or `push_*` in standard C++ containers. It allows you to construct the inserted object directly inside the container, passing all required […]

[Original post on techhub.social]
C++ code snippet comparing the effectivity of pushing expensive type into vector of variants vs emplacing it vs pushing back cheaper type and emplacing over that memory.
June 3, 2025 at 10:18 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 86 of #tuesdaycodingtips - Extendable logger pattern

I like my logs structured. If nothing else, I can log into a CSV file, load that CSV into Excel, turn on filters, and boom, I have a quite nice log analyzer tool. To get the maximum out of it, I need to […]

[Original post on techhub.social]
Code snippet that shows an example of an interface that breaks with every release. Somewhat better interface since all properties are encapsulated in a context struct.
May 20, 2025 at 11:02 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 85 of #tuesdaycodingtips - Incomplete types and name demangling

While writing type-safe APIs, a "tag" type is often useful. It is nothing more than a forward declaration of a type that will never be fully defined, just for the sake of creating a template […]

[Original post on techhub.social]
C++ code snippet showing how to demangle C++ identifiers under GCC/Clang and how a "tag" type can happen.
May 6, 2025 at 10:16 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 84 of #tuesdaycodingtips - C++ type trait for callable types

I recently asked myself: How do you make a reliable type trait for callable types so you can read their return values and call parameters?

The complexity lies in the fact that C++ has four […]

[Original post on techhub.social]
C++ code showing a type trait for reading callable type's parameters and return type.
April 29, 2025 at 10:09 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip XX of #tuesdaycodingtips - Curious case of NLOHMANN_JSON_SERIALIZE_ENUM

I recently debugged a case where code generated by NLOHMANN_JSON_SERIALIZE_ENUM failed at invariant assertions deep in the nlohmann_json library. When examined under a debugger, the […]

[Original post on techhub.social]
Expanded C++ implementation of NLOHMANN_JSON_SERIALIZE_ENUM macro.
April 8, 2025 at 12:47 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 82 of #tuesdaycodingtips - C# exception filter

Ever found yourself in the situation where you have an exact same handling code for two (or more) selected exception types? C# has a nice way of deduplicating said code.

A `catch` block, processing a base […]

[Original post on techhub.social]
C# code snippet demonstrating exception filter. c# snippet showing that you can use references to objects in scope in exception filter.
April 1, 2025 at 10:35 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 81 of #tuesdaycodingtips - Pattern matching a C++ enum

For a particular C++ application I wrote, I wanted to send an enum over a string-based protocol and pattern match on it on the receiving end to make sure that all possible values were handled.

You […]

[Original post on techhub.social]
C++ code demonstrating serialization through typeid with a concept for type safety, deserialization through template magic and then mattern matching on the resulting type.
March 4, 2025 at 12:44 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 80 of #tuesdaycodingtips - C# lambdas and mutability rules

Mutability rules in C# are funky. While trivial types are passed into functions by value, they are captured by reference for their usage in lambdas.

That can lead to stupid bugs - what if you […]

[Original post on techhub.social]
C# code that prints a loop control variable in a delayed lambda. C# code that copies the loop control variable into a local variable so it can correctly print it in a delayed lambda. Python code that demonstrates that you can capture a variable by copy in a lambda declaration. Python code that demonstrates that a range-based loop creates an iteration-local variables anyway.
February 18, 2025 at 11:47 AM
jakub-neruda.techhub.social.ap.brid.gy
Tip 79 of hashtag#TuesdayCodingTips - Many ways of collecting values from a map

How can you collect values from a std::map into some collection in C++? I know three basic ways to do so.

➤ A naïve imperative approach is manually iterating over the map and […]

[Original post on techhub.social]
C++ code that collects values from a map into a vector by iterating over the map and pushing the values into a target vector. C++ snippet that uses std::transform from the algorithms header to collect values from a map into a vector. C++ snippet that uses std::views::values and std::ranges::to to collect values from a map into a vector.
February 11, 2025 at 12:15 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 78 of #tuesdaycodingtips - Many ways to read a file in C++

In C#, you can easily read a whole file using `File.ReadAllText` method. Obviously, things can't be as easy in C++.

You can choose the 'old way' where you pre-allocate a buffer to which you can […]

[Original post on techhub.social]
C++ code snippet that loads a file into a string through seeking to the end of the file, figuring its size and then reading into a buffer of that size. C++ code snippet that converts an input stream into an iterator that can be used to initialize a string. C++ code snippet that redirects internal buffer of std::ifstream into a std::stringstream and extracting a string out of it.
January 28, 2025 at 12:12 PM
jakub-neruda.techhub.social.ap.brid.gy
Tip 77 of #tuesdaycodingtips - Multidimensional subscript operator

A quality-of-life C++23 feature has finally been integrated into Visual Studio (v17.12) after it was available in Clang (trunk) for quite some time. That feature is the support of the […]

[Original post on techhub.social]
C++ code implementing a custom class with multidimensional operator[]. A simple C++ sample using std::mdspan as a view over 1D array that behaves as a 3D array.
January 14, 2025 at 12:12 PM