Avoid ODR violations by using fixed types for protocol constants #244
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At least on Linux, constants such as AF_INET, SOCK_STREAM and IPPROTO_TCP are implemented with unnamed enums, which makes these constants have different types in different translation units. This results in ODR violations as protocol_type struct ends up defined differently in every TU. Also, static_protocol that is being instantiated with these constants also produces different types in each TU. While this by itself is not an ODR violation, it may generate lots of code and data duplication. Avoid all of the above by using fixed types for family, type and protocol constants in protocol_type and static_protocol. Use int for each of the types, following POSIX socket(2) signature. Fixes boostorg#242.
Collaborator
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In that case I might as well not bother defining the aliases and just use ints all the way? The unamed enum seems to be used that way anyhow. |
Member
Author
You could, but I kept the typedefs anyway as they are used in many places. It also offers an easy point of customization, if on some odd platform |
Member
Author
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The typedefs are also part of public interface, so removing them would be a breaking change. |
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At least on Linux, constants such as
AF_INET,SOCK_STREAMandIPPROTO_TCPare implemented with unnamed enums, which makes these constants have different types in different translation units. This results in ODR violations asprotocol_typestruct ends up defined differently in every TU.Also,
static_protocolthat is being instantiated with these constants also produces different types in each TU. While this by itself is not an ODR violation, it may generate lots of code and data duplication.Avoid all of the above by using fixed types for family, type and protocol constants in
protocol_typeandstatic_protocol. Useintfor each of the types, following POSIX socket(2) signature.Fixes #242.