isocpp / isocpp/CppCoreGuidelines

Provide a simple GSL utility to replace `static_cast<void>`

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#2,319 7 comments 0 reactions 1 assignee View on GitHub

@GabrielDosReis is already working on this.

Since Mar 5, 2026.

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Description

The guidelines recommend avoiding all cast (including static_cast). However, static_cast<void>(expr) is used (and blessed by the C++ standards) as a way to silence function calls whose results shouldn't be ignored. That can be seen as a gnarly hack. Instead, the GSL could provide a facility like

namespace gsl {
   template<typename T>
   inline void drop(T&&) { }
}

to use to ignore the value of an expression. No cast, intent preserved.

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