method has no return statement with switch
Hi! I have the error message: source/url.cache.d(20,16): Error: function url.Cache.UrlCache.doRequest has no return statement, but is expected to return a value of type string Inserting dummy return statement doesn't help. final switch / switch with default - no matter. As I understand compiler must detect when end of function is unreachable (and in fact it detects it - see comment about return ""; line) and do not try to check for return value. Is this my or compiler's error here? dmd --version DMD64 D Compiler v2.069.0 Copyright (c) 1999-2015 by Digital Mars written by Walter Bright [code] module url.Cache; import std.conv; import core.exception; import mysql.d; import std.digest.md; import std.net.curl; enum Method { GET="GET", POST="POST" } class UrlCache { // ... public string doRealRequest(string url, Method method) { final switch(method) { case Method.GET: return std.net.curl.get!AutoProtocol(url).text; case Method.POST: return std.net.curl.post(url, []).text; } // return ""; // produces 'statement is not reachable' warning, don't fix the problem } // ... } [/code]
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: Inserting dummy return statement doesn't help. final switch / switch with default - no matter. Try inserting assert(0); instead of a dummy return.
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 00:27:02 UTC, Adam D. Ruppe wrote: On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: Inserting dummy return statement doesn't help. final switch / switch with default - no matter. Try inserting assert(0); instead of a dummy return. Done, no difference.
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 00:30:29 UTC, crimaniak wrote: On Saturday, 7 November 2015 at 00:27:02 UTC, Adam D. Ruppe wrote: On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: Inserting dummy return statement doesn't help. final switch / switch with default - no matter. Try inserting assert(0); instead of a dummy return. Done, no difference. Wow, that impossible. You switch is well final. here DMD 2.068, linux x86_64 the folling compiles and runs: enum Method { GET="GET", POST="POST" } class UrlCache { public string doRealRequest(string url, Method method) { final switch(method) { case Method.GET: return std.net.curl.get!AutoProtocol(url).idup; case Method.POST: return std.net.curl.post(url, []).idup; } } } void main() {auto test = new UrlCache;} are you sure that the error you get doesnt come from another location ?!
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: Hi! I have the error message: source/url.cache.d(20,16): Error: function url.Cache.UrlCache.doRequest has no return statement, but is expected to return a value of type string [...] Because the "switch" is marked as "final", eventually one of cases will be followed. Because both cases have a "return" point, code will never get out of switch statement. So the compiler acts correctly.
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: [...] url.Cache.UrlCache.doRequest has no return statement, but is expected to return a value of type string [...] public string doRealRequest(string url, Method method) You posted the wrong code sample: your code shows doRealRequest but the message is about doRequest !
Re: method has no return statement with switch
On Saturday, 7 November 2015 at 06:02:49 UTC, BBaz wrote: On Saturday, 7 November 2015 at 00:21:57 UTC, crimaniak wrote: [...] url.Cache.UrlCache.doRequest has no return statement, but is expected to return a value of type string [...] public string doRealRequest(string url, Method method) You posted the wrong code sample: your code shows doRealRequest but the message is about doRequest ! Yes! It's just my inattention. Thanks! p.s. Don't program at 3 am