void f1() // Oops, forgot ;
void f2(); // Now a local declaration in the definition of f1().

Tom.

On 6/27/19 12:29 PM, Kyle Knoepfel via Std-Proposals wrote:
> Here’s an idea I’ve been thinking about a lot regarding functions composed of a single statement, and I’d like your thoughts.
>
> Consider the following function (and associated enumeration):
>
> enum class person {alice, bob, david};
> std::string_view greet(person const p)
> {
> switch(p) {
> case person::alice: return “Hello Alice.”sv;
> case person::bob: return “What’s up Bob?”sv;
> case person::david: return “(Avoid eye contact)”sv;
> }
> }
>
> In such a case, where there is no function-local state, I argue that the outer braces should be unnecessary:
>
> std::string_view greet(person const p)
> switch(p) {
> case person::alice: return “Hello Alice.”sv;
> case person::bob: return “What’s up Bob?”sv;
> case person::david: return “(Avoid eye contact)”sv;
> }
>
> Of course, once someone wants to introduce function-local variables that are otherwise not contained by the statement in the function, then braces are required:
>
> std::string greet(person const p)
> std::string const salutation{“Hi “}; // Error! Two statements in non-braced function definition.
> switch(p) {
> case person::alice: return salutation + "Alice.”;
> case person::bob: return salutation + “Bob.”;
> case person::david: return “(Avoid eye contact)”;
> }
>
> I also run into functions that are defined like:
>
> void print_results(std::vector<Result> const& results)
> {
> for (auto const& res : results) {
> std::cout << res << ‘\n’;
> }
> }
>
> An arguably better approach would be to do something like:
>
> for_all(results, [](auto const& res){ std::cout << res << ‘\n’; });
>
> but I occasionally run into situations where it may be more convenient to keep the explicit for loop:
>
> void print_results(std::vector<Result> const& results)
> for (auto const& res : results) {
> std::cout << res << ‘\n’;
> }
>
> Or consider the handling of simple member functions:
>
> template <typename T>
> class my_dumb_pointer {
> T* ptr_;
> public:
> T* get() const noexcept { return ptr_; } // vs
> T* get() const noexcept return ptr_; // Simpler? Not sure.
> };
>
> Function definitions with empty bodies would still require braces.
>
> Does this idea seem worth fleshing out? How difficult would it be for implementations to provide, if it was worthwhile?
>
> Thanks very much,
> Kyle Knoepfel