protocolbuffers/protobuf

Warning in repeated_ptr_field.h about conversion from `size_t` to `int` causes compiler error

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#23248 opened on Aug 27, 2025

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help wanted

Description

What version of protobuf and what language are you using? Version: main/v6.30.1 Language: C++

What operating system (Linux, Windows, ...) and version?

Windows

What runtime / compiler are you using (e.g., python version or gcc version)

MSVC 17.12.5

What did you do? I am compiling code that includes a generated .pb.h file.

What did you expect to see What did you see instead?

I am running into compiler warnings, which are treated as errors:

C:\dev\conan-cache\p\protoee6b55d34d238\p\include\google/protobuf/repeated_ptr_field.h(1575): error C2220: the following warning is treated as an error
C:\dev\conan-cache\p\protoee6b55d34d238\p\include\google/protobuf/repeated_ptr_field.h(1575): warning C4267: 'argument': conversion from 'size_t' to 'int', possible loss of data
C:\dev\conan-cache\p\protoee6b55d34d238\p\include\google/protobuf/repeated_ptr_field.h(1580): warning C4267: 'argument': conversion from 'size_t' to 'int', possible loss of data
C:\dev\conan-cache\p\protoee6b55d34d238\p\include\google/protobuf/repeated_ptr_field.h(1584): warning C4267: 'argument': conversion from 'size_t' to 'int', possible loss of data
C:\dev\conan-cache\p\protoee6b55d34d238\p\include\google/protobuf/repeated_field.h(145): warning C4267: 'argument': conversion from 'size_t' to 'const _Ty', possible loss of data

I believe that this issue still exists in the codebase:

Anything else we should know about your project / environment

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