From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by sourceware.org (Postfix) with ESMTPS id 820183858D35 for ; Thu, 9 Nov 2023 21:12:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 820183858D35 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 820183858D35 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a00:1450:4864:20::62b ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699564329; cv=none; b=SD6NWtTSPgC2zUuiANrWorHmXldphE5wZs18HaKknJD4bY49mGb+LnaUxVofaJOUrtDgr8GqOnbWfOnD8UE5kevAH8kDNpzeLpUZp9k8Dr02VQqrymXoGlc2aksp6z/Yy30F0Ru49B2Th0uecFOVA/1hehbl/wDcoOSOmpRjtZo= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699564329; c=relaxed/simple; bh=MX+9KgIMDE8ssvQAF2nPl8XOEYoeTvFW7Wib3zMvf68=; h=DKIM-Signature:MIME-Version:From:Date:Message-ID:Subject:To; b=mlF3aNTkuCgXgZErVhtsvFqN6IagWR03mug4VT0hg1dISaBjrXRFSBuiYv2kwTJ3x7871VTK1CBhaPeScjX5kEGBPX9aYIukUoJkfWU/DsMlsTN6F1Dj/Dt0WNCywHizaLv7oMqlvxTShMLI8RsYVkyjiyRBV7sHmLKr9Ddlmtk= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-9c2a0725825so233049666b.2 for ; Thu, 09 Nov 2023 13:12:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699564326; x=1700169126; darn=gcc.gnu.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=64CncCwxQfZLLp9+eSOUUMrB7hPwizWi8usyG7Vd06c=; b=CjaVCUrSNYSEpXCWDOve36RxLCI+KEvTKZaD4TheqfEJLapYo3BzLqgKu3dNidcY48 qHrkZbsaMrugmIJRb+6qaOyHv0/sT0RuUw0usJXDllZtlhyC1z6vHi73dOecI5q4RyRN 779oCDPq4vYpdM9DCu0aba2+2HffC+Ug1Joa07U7uIEoAfG2hyEowIJN2cvsUZiRAkFn otANf4Eb5jY9jsj2bCwRuauaawchX/AQejocea31iUCUTOuaJyh8cO4Ze3OIG4+RvELN 91ZDnLxrBcOxqSCBOR+3GOKLYAsjiOyM7rKGpuV5KgAavoePeV+wpJlBaj6Bvmn5Th0n n0HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699564326; x=1700169126; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=64CncCwxQfZLLp9+eSOUUMrB7hPwizWi8usyG7Vd06c=; b=ifsU1qoGrLQfTM6piAjOWeNgOruHnIpwdIY4H/wqEgjQxFWkR1t00+EFDmbueubbYq Sx6JbNBNPkSofeSI7v7g6VQKmRELYxizQijptOd+vCN3HZoJuzVBaW6gqAelWNLSdtd5 5uqvBSvNl/NjiRTsWLk00WkQx/UY0hAEXpSNSNnmPWOxPNV8yUE8Xb/iIR8H4fdN0ZVi MlbvzF2lPjkWfJWCOTirUF8QOb2FIKvYH/VrMsiYHN6t2o0MUTpOrtS0LvSsfNGYPHRL BC5Hc95q6imrBzBytlwGZsNb9ud/8bUHCtLu8Kyffl31f0oueqYqNmHn8NkvcI7CZkzf R+qQ== X-Gm-Message-State: AOJu0Yy69CvOEQ1oh+yL/l3WBNjC7CZl6oN0o2OmM3QGN9vWl/sdISfT CGgb8o6a88HOn26N5NmEDF43k2WoImU0PiDndig= X-Google-Smtp-Source: AGHT+IEsIecTt7bpGutYyKzSi2QKlAUOlD7YcepPRjSMMtQd6CzHhMV61QpZfROkp/0v5K7b4EpDHVhAcLDcWi9qbOg= X-Received: by 2002:a17:907:9304:b0:9dd:973b:2753 with SMTP id bu4-20020a170907930400b009dd973b2753mr4904828ejc.15.1699564325944; Thu, 09 Nov 2023 13:12:05 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Jonathan Wakely Date: Thu, 9 Nov 2023 21:11:54 +0000 Message-ID: Subject: Re: Can you use a function reference passed in a template argument? To: Arthur Schwarz Cc: gcc-help@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-0.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, 9 Nov 2023 at 20:46, Arthur Schwarz wrote: > > > Is there any way to use a function passed as an argument to a template > (example below)? Couldn't the existence of the referenced function be > established durint instantiation (Stack obj)? I realize that > just doing analysis of the template that the existence of a referenced > function can't be determined, but during instantiation it can be validate= d. I have no idea what that code is trying to do. You're trying to call a member function on a _type_ T. And you said you want to call a function passed as an argument ... but the template argument you pass is a type, not a function. > > As a nit, the repeated instances of "../header/" in the error message is > an annoyance. That looks like a problem with symlinks or your build system, not gcc's fau= lt. > > Diagnostic message and code given below. > > thanks > art > > ../header/../header/../header/../header/Stack.h: In member function > =E2=80=98std::string Stack::toString()=E2=80=99: > ../header/../header/../header/../header/Stack.h:184:46: error: expected > primary-expression before =E2=80=98.=E2=80=99 token > 184 | str << setw(3) << s.size() << ": " << T.toString(); > | ^ > > # include > # include > > using namespace std; > template > class Stack { > string toString() { > stringstream str; > str << setw(3) << s.size() << ": " << T.toString(); > return str.str(); > }; > }; >