Does C++Builder 12.0 support C++20 modules?

Question

RAD Studio 12.0 has been released, and they supposedly upgraded C++Builder to Clang 15, but I can't find the module feature of C++20, is there any explanation?

Answer 1

The Clang 15 upgrade only applies to the Windows 64bit preview compiler, not to the rest of C++Builder's compilers, which are still based on Clang 3.3 and 5.0.

Per C++Builder 12.0's documentation:

Clang-enhanced C++ Compilers

RAD Studio provides the following Clang-enhanced C++ compilers:

Compiler	Platform	Clang Version	LLVM Version
BCC32C	32-bit Windows	5.0	5.0
BCC32X	32-bit Windows	5.0	5.0
BCC64	64-bit Windows	5.0	5.0
BCC64X	64-bit Windows	15.0	15.0
BCCIOSARM64	64-bit iOS	3.3	3.5
BCCAARM	Android	3.3	3.3

Also:

Modern C++ Language Features Compliance Status

Note: C++2c is expected to be C++26.

Note: BCC64X is currently a Preview. The below status is aspirational but untested and is not a guarantee of the final support. BCC64X uses C++17 as its default language level, and the initial release is not planned to support higher language levels. To compile to C++2c, run bcc64x with -std=c++2c.

Note: C++23 is partially supported by the Clang version that BCC64X is based on and the C++ RTL and STL (libc+) that it uses. We expect that any language feature supported by both the Clang and the libc++ in versions 15 and earlier, work correctly. But it is not supported, even at the unsupported level that a Preview implies. However, the Preview of the BCC64X compiler currently aims at C++17 as its language standard. You can use -std=c++23 to change the target language compliance.

Note: C++20 is partially supported by the Clang version that BCC64X is based on and the C++ RTL and STL (libc++) that it uses. We expect that any language feature supported by both the Clang and the libc++ in versions 15 and earlier, work correctly. But it is not supported, even at the unsupported level that a Preview implies. However, the Preview of the BCC64X compiler currently aims at C++17 as its language standard. You can use -std=c++20 to change the target language compliance.

There is currently no mention in the documentation of support for specific features that are introduced after C++17.