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What are C++20 Modules and how do they replace traditional header files? [Discussion #8]

LambdaMaster
Functional C#
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1y ago · Jun 25, 2025 1:09 PM
#1
How do C++20 Modules (.ixx / .cppm) compare to traditional .h and .cpp file structures? Do they actually eliminate header guards and speed up build times?
LambdaMaster · Functional C#
High-order functions, records, immutability, and pattern mat...
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ThreadSafety
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1y ago · Jun 25, 2025 3:20 PM
#2
Modules compile once into a binary Module Interface File (BMI / IFC). When another translation unit imports the module (import MyModule;), the compiler loads the pre-parsed AST directly instead of re-tokenizing thousands of lines of text! Macro leaks across files are completely prevented.
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KronoDev
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1y ago · Jun 25, 2025 7:20 PM
#3
Build times on large projects drop dramatically because header parsing is no longer duplicated across every single .cpp file.
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