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https://issues.apache.org/jira/browse/THRIFT-5637?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17888655#comment-17888655
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Alkis Evlogimenos commented on THRIFT-5637:
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I have created [https://github.com/apache/thrift/pull/3037] to address this.
Emitting aggregates speeds up decoding by 10% because the compiler can generate
better constructors and/or inline them.
> Thrift compiler should be able to output c++ Aggregate types
> ------------------------------------------------------------
>
> Key: THRIFT-5637
> URL: https://issues.apache.org/jira/browse/THRIFT-5637
> Project: Thrift
> Issue Type: Improvement
> Components: C++ - Compiler
> Affects Versions: 0.16.0, 0.17.0
> Reporter: Benjamin Gemmill
> Priority: Major
> Time Spent: 10m
> Remaining Estimate: 0h
>
> If we have a thrift struct defined like this:
> {{struct thingamabob {}}
> {{ 1: i64 a = 0}}
> {{ 2: i64 b = 0}}
> {{ 3: i64 c = 0}}
> {{}}}
> Then the generated code contains a few constructors and assignment operators
> that look like this:
> {{thingamabob(const thingamabob&) noexcept;}}
> {{thingamabob&operator=(const thingamabob&) noexcept;}}
> {{{}thingamabob() noexcept{}}}{{{}: a(0),{}}}{{{}b(0),{}}}{{{}c(0)
> {{}}}{{{}}{}}}
> The issue here is that while this class could be an
> [AggregateType|http://example.com] and support aggregate initialization, the
> way these defaults are generated prevent it.
> If instead, thrift used default initializers like this where the the member
> objects are defined:
> int64_t a\{0};
> int64_t b\{0};
> int64_t c\{0};
> We could then initialize thrift structs with initializer lists, expect
> static_assert(std::is_aggregate_v<type>) to work, and we'd still have default
> construction and copying.
>
> For this to work, the "templates" option passed to the c++ compiler should
> remove the virtual keyword from the generated printTo functions, and the
> generated __isset structs would also need to be changed similarly to look
> like:
> {{typedef struct_thingamabob__isset {}}
> {{bool a :1\{false};}}
> {{bool b :1\{false};}}
> {{bool c :1\{false};}}
> {{} _thingamabob__isset;}}
>
> {{Happy to take a stab at this and wanted to check for feedback first.}}
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