Why Rust closures are somewhat hard

Re:Why Rust closures are somewhat hard by whyever on Monday September 10, 2018 @03:40PM (#17954509)

C does not have `auto`, so you couldn't store closures in local variables.

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Re:Why Rust closures are somewhat hard by v_lisivka on Monday September 10, 2018 @03:54PM (#17954642)

In C, you can use typeof().

  #define max(a,b) \
  ({ typeof (a) _a = (a); \
      typeof (b) _b = (b); \
    _a > _b ? _a : _b; })

https://gcc.gnu.org/onlinedocs/gcc/Typeof.html

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Re:Why Rust closures are somewhat hard by wahern on Monday September 10, 2018 @04:17PM (#17954841)

typeof is supported by everything[1] except the C standard. It was rejected in the 1990s and nobody on the committee seems to want to revisit the decision.

To be fair, typeof is not as useful without statement expressions (`({ ... })`), and statement expressions aren't as widely supported.

[1] All the major compilers support it (clang, GCC, IBM, Intel, Microsoft, Solaris, etc), plus or minus underscores in the identifier.

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Re:Why Rust closures are somewhat hard by Longhanks on Monday September 10, 2018 @04:02PM (#17954723)

You’re not wrong, but C has __auto_type (at least GCC and clang support it, no idea about MSVC): https://gcc.gnu.org/onlinedocs/gcc/Typeof.html

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Re:Why Rust closures are somewhat hard by int_19h on Monday September 10, 2018 @05:03PM (#17955174)

It's a language extension, not standard C.

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