#pragma once

directive in C and C++ provided as a language extension

Thing directive Q307472

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#pragma once

Summary

pragma once is a directive^[1]. #pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).^[2]

Key Facts

pragma once's instance of is recorded as directive^[3].
pragma once's instance of is recorded as de facto standard^[4].
pragma once's Freebase ID is recorded as /m/0948fm^[5].
pragma once's replaces is recorded as #include guard^[6].
pragma once's used by is recorded as C preprocessor^[7].
pragma once's has effect is recorded as idempotence^[8].

Why It Matters

pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).^[2] #pragma once has Wikipedia articles in 9 language editions, a strong signal of global cultural recognition.^[9]

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Quick Facts

Instance of directive, de facto standard

Properties

Has effect idempotence

Replaces #include guard

Used by C preprocessor

External References (1)

Freebase id /m/0948fm

🌐 Available in 9 languages

enPragma once esPragma once faPragma once frPragma once plPragma once ptPragma once ruPragma once ukPragma once zhPragma once

🏷️ Also known as

en pragma once en #Pragma once

🔗 Connections

Instance of 2

de facto standard, directive

Has effect 1

idempotence

Replaces 1

#include guard

Used by 1

C preprocessor

← Replaced by 1

#include guard

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). #pragma once. Retrieved May 3, 2026, from https://4ort.xyz/entity/pragma-once

MLA “#pragma once.” 4ort.xyz Knowledge Graph, 4ort.xyz, 3 May. 2026, https://4ort.xyz/entity/pragma-once.

BibTeX

@misc{4ortxyz_pragma-once_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{#pragma once}}, year = {2026}, url = {https://4ort.xyz/entity/pragma-once}, note = {Accessed: 2026-05-03}}

LLM prompt

According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): #pragma once — https://4ort.xyz/entity/pragma-once (retrieved 2026-05-03)

Canonical URL: https://4ort.xyz/entity/pragma-once · Last refreshed: May 3, 2026

#pragma once

#pragma once

Summary

pragma once is a directive[1]. #pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).[2]

Key Facts

pragma once's instance of is recorded as directive[3].

pragma once's instance of is recorded as de facto standard[4].

pragma once's Freebase ID is recorded as /m/0948fm[5].

pragma once's replaces is recorded as #include guard[6].

pragma once's used by is recorded as C preprocessor[7].

pragma once's has effect is recorded as idempotence[8].

Why It Matters

pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).[2] #pragma once has Wikipedia articles in 9 language editions, a strong signal of global cultural recognition.[9]

References

Direct Wikidata claims

Class ancestry

Aggregate / graph-position facts

📑 Cite this page

pragma once is a directive^[1]. #pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).^[2]

pragma once's instance of is recorded as directive^[3].

pragma once's instance of is recorded as de facto standard^[4].

pragma once's Freebase ID is recorded as /m/0948fm^[5].

pragma once's replaces is recorded as #include guard^[6].

pragma once's used by is recorded as C preprocessor^[7].

pragma once's has effect is recorded as idempotence^[8].

pragma once draws 449 Wikipedia views per month (directive category, ranking #1 of 1).^[2] #pragma once has Wikipedia articles in 9 language editions, a strong signal of global cultural recognition.^[9]