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Core Syntax
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Types
integral types floating types arrays slices associative arrays tuples structs unions enums alias declarations
Functions
functions ref parameters out parameters default arguments variadic functions function literals delegates UFCS pure functions nothrow functions
Templates
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Ranges
input ranges forward ranges bidirectional ranges random access ranges map filter reduce take zip lazy evaluation
OOP
classes interfaces inheritance virtual methods final methods abstract classes properties operator overloading opDispatch object lifetime
Memory and Safety
GC allocation scope lifetime RAII structs @safe @trusted @system bounds checking synchronized shared core.atomic
Errors and I/O
exceptions try catch finally assert enforce File readText writeln formattedWrite unit tests contracts in out do
D / Errors and I/O

File

Learn File in D with a construct-specific explanation, unique example, engineering boundary, and mastery check.

10 min read • Advanced

File is a focused D topic inside Errors and I/O. This lesson explains the construct itself, the state or value it operates on, and the observable result it produces.

Read the example as a small executable experiment. Identify the exact syntax that belongs to File, then change one input and predict the result before running it.

Topic-specific example

d-08-05-file.d
d Try It Live 
import std.stdio: File; auto f=File("out.txt","w"); f.writeln("ok");
Edge case / engineering note

File has rules that are easy to miss when the example is copied mechanically. Check the feature-specific boundary shown by this construct: scope, mutability, evaluation order, type constraints, lifetime, error behavior, compile-time restrictions, or resource cleanup where applicable.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

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