MQL5 Macros, Inline Expansion, and Code Size Trade-Offs

Summary

This programming tutorial explains MQL5 preprocessor macros through a comparison with inline functions. It presents inline expansion as replacing a function call with its body at the call site, which may increase executable size and memory use. The author notes that they did not observe a meaningful execution-speed difference from using the inline keyword in their examples, so the possible speed benefit is presented as uncertain rather than demonstrated.

The article then shows how a multi-line macro can be represented as a single preprocessor definition using line-continuation characters. Fibonacci examples illustrate recursive and iterative calculations and how code can be expanded into a local block. The discussion emphasizes that macros are compile-time substitutions and require care with scope, variable names, and definition boundaries. It is a programming explanation rather than a trading method: it offers no market analysis, strategy evidence, or measured benchmark, and its claims about compiler behavior are framed partly as the author's understanding.

Key ideas

• An inline function may be expanded at its call sites, potentially increasing executable size and memory use.
• The author reports no noticeable speed difference from using or omitting inline in the examples.
• A multi-line macro is written as one preprocessor definition continued across source lines.
• Macros substitute code during preprocessing, so expanded blocks need careful handling of local variables and scope.
• The Fibonacci examples explain programming mechanics and do not test a trading strategy.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.