Overview

Working on legacy projects

The compilation pipeline

Who is this course for and prerequisites

Welcome

What will you learn in this course

Multi-targeting

Adding multi-targeting

What is target framework moniker (TFM)

Using init-only and required properties in .NET Framework

C Language version vs. Target framework

Compiler language specific types

PolySharp- source-only polyfills for C Language

Using PolySharp for init-only and required properties

Choosing the right C Language version

'latest' vs. specific C Language version

Conclusion

Overview 2

Using Directory.Build.props

Module Overview

Storage Model- Inline vs. Indirection

Exploring Storage

Analyzing Storage Model with Benchmarks

Inspecting Type Layout (part 2)

Exploring Access Patterns with Benchmarks

Copy Semantics- Assignment

Analyzing Access Patterns Benchmark Results

Copy Semantics- Parameter Passing

Equality Semantics

Summary

Overview 3

Object Initialization

Analyzing Object Construction Order

Using Analyzers to Avoid Making Virtual Calls in Base Constructors

A Custom Factory Method and Error Handling

Virtual Calls in the Base class Constructor

Exploring a Custom Factory Method Behavior at Runtime

Benchmarking the new() Constraint

Overview 4

The Readonly Field Trap

Conclusion 2

Boxing and Indexers

Exploring Different Kind of Copies

Why the Compiler Makes a Copy

Defensive Copy Overview

Manual Value-based Equality

Overview 5

How to Avoid Defensive Copies for Structs

Conclusion 3

Referential and Value-based Equality

Records Under the Hood

Issues With the Default Structs Equality

Overview 6

Records Limitations

Record Structs vs. Default Structs

System.Tuple vs. System.ValueTuple

Knowing the Limits- When to Move to Actual Types

Union Types- Why Do We Need Them

Union Types- the Basics

Union Types Under the Hood

Tuples in C

Overview 7

UnionTypes - Recap

Section Overview

Argument Validation and Nullable Reference Types

Conclusion 4

Union Types- the Deep Dive

Argument Null Checks in C

Checking for Null in C

Implementing Custom String Validation

Recreating ThrowIfNull Manually

Issues With Nullable Strings in .NET Framework

Analyzing ThrowIfNull Boxing Allocations

Overview 8

Summary 2

The issue with Multi-Targeting

Refactoring to Extension Everything

Extension Methods

Creating Polyfills for Argument Validation

Overview 9

Summary 3

Lambdas Are Ubiquitous

Extending the C Language

Lambdas Under the Hood

Benchmarking Lambda Expressions

NET 10 Delegate De-Abstraction

Profiling Closure Allocations

Method Group Conversion vs. Lambda Expressions

Issues With Capturing Loop Variables

Scope-based Code Generation for Lambda Expressions

Method Group Conversion vs. Lambda Expressions in Action

Overview 10

Imperative vs. Declarative Code

Pattern Matching Exhaustiveness

Recursive Patterns Explained

Two Dimensions of Pattern Matching

Exhaustiveness Checks in Action

Open and Closed Hierarchies

Exhaustiveness Checks for Classes and Unions

Know When to Stop

Section Overview 2

Iterator Design Pattern in C

Overview 11

The Cost of Boxed Iterators

Foreach Under the Hood

Foreach and IEnumerable

Iterator as a State Machine

Enumerable De-Abstraction in .NET 10

Iterator as a Mutable Struct

Overview 12

Manual Iterator Implementation

Summary 4

Refactor To Use Iterator Blocks

Iterator Block Execution Semantics

Lowered C Code for Generated State Machines

State Machine Under the Hood

Benchmarking State Machine Allocations

State Machine Allocations

Resources in Iterator Blocks

De-Abstracting Iterator Blocks in .NET 10

Error Handling in Iterator Block

Overview 13

Two Syntaxes, One Model

Query Comprehensions vs. Method Calls

What Is IEnumerable-T-

Multiple Enumerations with IEnumerable-T-

Overview 14

LINQ Deferred Execution Model

Using Static Analysis to Avoid Multiple Enumerations

Summary 5

LINQ Performance Reputation

Analyzing Enumerable.Any Performance

LINQ vs. Manual Loop Performance Analysis

Mastering LINQ Performance

Performance Optimization Loop

Spanification in LINQ

LINQ Performance Improvements in .NET 10

Iterator Fast Path Overrides

LINQ Performance Optimization Patterns

Iterator Fusion

Type-based Specialization

For loop vs. Enumerable.SequenceEquals

Vectorization in .NET Framework

Conclusion 5

Summary 6