docs: RFC 10 on C++17 minimum standard support (#4566)

doc/development/rfc/README.md

@@ -16,6 +16,8 @@ A list of all GRASS GIS RFC documents, with status:
 - [RFC 7: Language Standards Support](language_standards_support.md) (Adopted)
 - [RFC 8: Python Language Support](python_language_support.md) (Adopted)
 - [RFC 9: Version Numbering](version_numbering.md) (Adopted)
+- [RFC 10: C++17 Language Standard Support](RFC10_cpp17_language_standards_support.md)
+  (Adopted)
 - [RFC X: Release Policy](https://github.com/OSGeo/grass/pull/3673) (Draft)
 
 Status values:

doc/development/rfc/RFC10_cpp_language_standards_support.md

@@ -0,0 +1,35 @@
+# RFC 10: C++17 Standard Support for GRASS GIS 8.5
+
+Author of the first draft: Nicklas Larsson
+
+Status: Motion passed, 28 November 2024
+
+## Summary
+
+Set a new minimum build requirement for C++ code to support the C++17 standard. This
+supersedes the [RFC 7: Language Standards Support](language_standards_support.md)
+with respect to C++ standard support.
+
+## Background
+
+The RFC 7, which set the minimum supported C++ standard to C++11, was adopted 3.5
+years ago. At that time, although the latest versions of common compilers had
+full support for C++17, neither the GRASS GIS code itself nor its dependencies
+needed or required it. Now, compilers with full C++17 support are available also
+in what may be considered stable or long-term-support systems.
+Moreover, important dependencies such as PDAL 2.4 (released in March 2022) and
+GDAL 3.9 (May 2024) require C++17 support, and so will the future release of
+GEOS 3.14.
+
+## C++17 standard for GRASS GIS
+
+The time has come to increase the minimal C++ standard support for GRASS GIS
+code to the C++17 standard. This enables the use of new C++17 features, if and when
+so is needed or recommended. There is, however, no need to make any immediate
+changes to current code. Continuous integration runners already compile in
+C++17 mode, making sure nothing will be broken.
+
+## References on C++17 features and support
+
+- [Wikipedia](https://en.wikipedia.org/wiki/C%2B%2B17)
+- [cppreference.com](https://en.cppreference.com/w/cpp/17)