220 8132 article Path: news.gmane.org!not-for-mail From: Michael Price - Dev Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: A compile-time string literal library type Date: Sun, 15 Dec 2013 19:26:59 -0800 (PST) Lines: 1458 Approved: news@gmane.org Message-ID: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_1040_29659157.1387164419726" X-Trace: ger.gmane.org 1387164416 10360 80.91.229.3 (16 Dec 2013 03:26:56 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 16 Dec 2013 03:26:56 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC63BP4Z2YBRBBHGXGKQKGQEKCZSBPQ@isocpp.org Mon Dec 16 04:27:03 2013 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ie0-f200.google.com ([209.85.223.200]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VsOph-0004Ih-Vg for gclcip-std-proposals@m.gmane.org; Mon, 16 Dec 2013 04:27:02 +0100 Original-Received: by mail-ie0-f200.google.com with SMTP id at1sf16348189iec.3 for ; Sun, 15 Dec 2013 19:27:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:list-subscribe:list-unsubscribe:content-type; bh=VJwBB79YxIpzw0drkrnl20Z7ls1TTt0XzlskyZnrB70=; b=XU15LFbn/Md+oVsINbpOQlkmb7A1IDTCKJvAvK2NJ4zG8ISwVO6gKAA0qZbXBIl058 CyGZh80//bFc+nFgV3ZJ3w9MMLn/ROwedB1c4RzJer84QeCnkqAqRzYZsItDVSa3aFLk QuukBka8J3XsbHFMqdcZLUG5N/KaDeF961wW1gC9Vi29seyYKAYLl2d4j828ofRBxcSC FC665Jji4HhZr+nJVrzDIlkUf9by/qNWqjbQ0PZuOTyHnwasvGOyFX62mLBeM2bcRiLV nVGQnW2/B/+QRNyG6MS2+KCDUcdrRjmQKj+VQrnESWhBgCk1RSSFL+rTnX37v13TQsny UMhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:message-id:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=VJwBB79YxIpzw0drkrnl20Z7ls1TTt0XzlskyZnrB70=; b=LDrO/CIaF5vJGrZ3bwLVEKjnPk6pPCDRwhW685WG9oXXkXMJoG2jHm366vugG1dHDi tmpgw+I1IBy+V8KCbFq496caT5AJPUN7tGkRn0pC2XY+G/oNjTqTcYdPVEdWCMNxPNr3 K2xY6PU6TUaERSdCB6hPmYRWzpcov7QmtWi6xseYVeBvCWhX9MyIuiSbLAJy1CFVxD7O MxLRH9J8Lh9IiBoYWXdn8SblqetLz5cqO3CCdAUHONaALkwe7fHHF4wA5O5XZiV3QAc5 wHIupqLhWva96QwUQDJ4yiDqu8U5TcRoOMS9cjLyLZy0luS/MKTRfem0CBjYCk0Nd3NV JCWw== X-Gm-Message-State: ALoCoQlwdinVQBAiR02KvXJvagKo6CYu4RnSY/wijBstziTtTySMP/jM9f2UV3q2sT1TL7KVAOf0 X-Received: by 10.182.243.166 with SMTP id wz6mr5312101obc.19.1387164421038; Sun, 15 Dec 2013 19:27:01 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.49.82.49 with SMTP id f17ls1982164qey.54.gmail; Sun, 15 Dec 2013 19:27:00 -0800 (PST) X-Received: by 10.49.104.69 with SMTP id gc5mr82qeb.23.1387164420347; Sun, 15 Dec 2013 19:27:00 -0800 (PST) X-Original-Sender: michael.b.price.dev@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:8132 Archived-At: ------=_Part_1040_29659157.1387164419726 Content-Type: text/plain; charset=ISO-8859-1 I'm considering writing up a proposal to standardize a library type that represents a compile-time sequence of character literals. I'm looking for a first round of feedback. You can view my prototype implementation at https://github.com/michaelbprice/cxx_snippets/blob/master/string_literal/string_literal.cpp I'm using the top-of-trunk clang to compile with the following command-line: clang++ -std=c++1y string_literal.cpp -Wno-gnu-string-literal-operator-template At the moment, my "test" code looks like this: void testSizes() { static_assert("He"_cs.size() == 2, "size() is wrong"); static_assert(L"Wo"_cs.size() == 2, "size() is wrong"); static_assert(u"Hello!"_cs.size() == 6, "size() is wrong"); static_assert(U"World!"_cs.size() == 6, "size() is wrong"); } void testEmptyStrings() { constexpr auto mb = ""_cs; constexpr auto wide = L""_cs; constexpr auto utf16 = u""_cs; constexpr auto utf32 = U""_cs; static_assert(mb.size() == 0, "Multi-byte size() is wrong"); static_assert(wide.size() == 0, "Wide size() is wrong"); static_assert(utf16.size() == 0, "UTF-16 size() is wrong"); static_assert(utf32.size() == 0, "UTF-32 size() is wrong"); static_assert(mb.length() == 0, "Multi-byte length() is wrong"); static_assert(wide.length() == 0, "Wide length() is wrong"); static_assert(utf16.length() == 0, "UTF-16 length() is wrong"); static_assert(utf32.length() == 0, "UTF-32 length() is wrong"); static_assert(mb.empty() == true, "Multi-byte empty() is wrong"); static_assert(wide.empty() == true, "Wide empty() is wrong"); static_assert(utf16.empty() == true, "UTF-16 empty() is wrong"); static_assert(utf32.empty() == true, "UTF-32 empty() is wrong"); static_assert(mb == ""_cs, "operator==() is wrong"); static_assert(mb != " "_cs, "operator!=() is wrong"); } void testSearching() { constexpr auto hi = "Hello "_cs + "World!"_cs; static_assert(hi.find('?') == std::string::npos, "find() is wrong"); static_assert(hi.find(' ') == 5, "find() is wrong"); static_assert(hi.find('o') == 4, "find() is wrong"); static_assert(hi.find("orl"_cs) == 7, "find() is wrong"); static_assert(hi.rfind('o') == 7, "rfind() is wrong"); static_assert(hi.rfind("el"_cs) == 1, "rfind() is wrong"); } void testSubstringFunctions() { constexpr auto big = "Hello, World!"_cs; constexpr auto smaller = big.substr<7>(); constexpr auto lessbig = big.cdr(); static_assert(smaller.size() == 6, "substr<>() is wrong"); static_assert(smaller[0UL] == 'W', "substr<>() is wrong"); static_assert(big.substr<0>().at(0) == 'H', "substr<>() is wrong"); static_assert(big.substr<12>().at(0) == '!', "substr<>() is wrong"); static_assert(big.size() == lessbig.size() + 1, "cdr() is wrong"); } void testComparisons() { constexpr auto first = "One"_cs; constexpr auto second = "Two"_cs; constexpr auto last = "One"_cs; static_assert(first.compare(last) == 0, "compare() is wrong"); static_assert(first.compare(second) == -1, "compare() is wrong"); static_assert(second.compare(last) == 1, "compare() is wrong"); static_assert("A"_cs == "A"_cs, "operator== is wrong"); static_assert("A"_cs != "a"_cs, "operator!= is wrong"); static_assert("a"_cs > "A"_cs, "operator> is wrong"); static_assert("1"_cs < "2"_cs, "operator< is wrong"); } void testConversions() { static_assert("0"_cs.to_number() == 0, "to_number() is wrong"); static_assert("1"_cs.to_number() == 1, "to_number() is wrong"); static_assert("11"_cs.to_number() == 11, "to_number() is wrong"); static_assert("65535"_cs.to_number() == 65535, "to_number() is wrong"); //"99kj343"_cs.to_number(); constexpr ptrdiff_t number = "12345"_cs; static_assert(number == 12345, "operator size_type is wrong"); //constexpr ptrdiff_t positive = "+1"_cs; //static_assert(positive == 1, "to_number() is wrong"); } void testConcatenation() { constexpr auto hello = "Hello"_cs; constexpr auto world = "World"_cs; constexpr auto together = hello + ", "_cs + world + "!"_cs; static_assert(together.size() == 13, "operator+ is wrong"); static_assert(together[5UL] == ',', "operator+ is wrong"); } template struct star_wars_speaker { star_wars_speaker() { std::cout << "Someone in Star Wars" << std::endl; } }; template <> struct star_wars_speaker { star_wars_speaker() { std::cout << "Carrie Fisher" << std::endl; } }; template <> struct star_wars_speaker { star_wars_speaker() { std::cout << "James Earl Jones" << std::endl; } }; template <> struct star_wars_speaker { star_wars_speaker() { std::cout << "Liam Neeson" << std::endl; } }; void testClassTemplates() { auto one = star_wars_speaker(); auto two = star_wars_speaker(); auto thr = star_wars_speaker(); auto fur = star_wars_speaker(); } template void star_trek_speak(const Str &) { std::cout << "Someone in Star Trek" << std::endl; } template <> void star_trek_speak(const decltype("Illogical captain"_cs) &) { std::cout << "Leonard Nimoy" << std::endl; } template <> void star_trek_speak(const decltype("He's dead Jim"_cs) &) { std::cout << "DeForest Kelley" << std::endl; } template <> void star_trek_speak(const decltype("Oh my"_cs) &) { std::cout << "George Takei" << std::endl; } void testFunctionTemplates() { star_trek_speak("Illogical captain"_cs); star_trek_speak("He's dead Jim"_cs); star_trek_speak("Oh my"_cs); star_trek_speak("Khaaaaaaaaaaannnnnn!"_cs); } int main() { testSizes(); testEmptyStrings(); testSubstringFunctions(); testComparisons(); testConversions(); testConcatenation(); testClassTemplates(); testFunctionTemplates(); return 0; } -- --- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/. ------=_Part_1040_29659157.1387164419726 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I'm considering writing up a proposal to standardize a lib= rary type that represents a compile-time sequence of character literals. &n= bsp;I'm looking for a first round of feedback.  You can view my protot= ype implementation at https://github.com/= michaelbprice/cxx_snippets/blob/master/string_literal/string_literal.cpp

I'm using the top-of-trunk clang to compile with the f= ollowing command-line:

clang++ -std=3Dc++1y string_literal.cpp -Wno-gnu-string-lit= eral-operator-template

At the moment,= my "test" code looks like this:

void testSizes()
=
{
  &nbs= p; static_= assert("He"_cs.size() =3D=3D 2, "size() is wrong");
    static_assert(L"Wo"_cs.size() =3D=3D 2, "size() is wrong");
    static_assert(u"Hello!"_cs.size() =3D=3D 6, "size() is wrong");
    static_assert(U"World!"_cs.size()<= /span> =3D=3D 6, "size() is wrong");
}

v= oid testEm= ptyStrings= ()
{
    constexpr auto mb =3D ""_cs;=
    constexpr au= to wide =3D L""_cs;
    constexpr auto utf16 =3D u= ""_cs;
    constexpr= auto utf32 =3D U""_cs;

&= nbsp;   static_assert(mb<= /span>.size() =3D=3D 0, "Multi-b= yte size() is wrong");
    static_assert(wide.<= /span>size= () =3D=3D 0, "Wide size() is wrong");
    static_assert(utf16.size() =3D=3D 0, "UTF-16 size() is wrong");
    static_assert(utf32.size() =3D=3D 0, "UTF-32 size() is wrong");

    static_assert(mb.length() <= /span>=3D=3D 0, "Multi-byte length() is wrong");
    static_assert(wide.length() =3D=3D = 0, "Wide length() is wrong");
    static_assert(utf16.length() =3D=3D 0= , "UTF-16 length() is wrong");
    static_asser= t(<= span style=3D"color: #000;" class=3D"styled-by-prettify">utf32.length() =3D=3D 0, "UTF-32 length()= is wrong"= );

=     static_assert(mb= .empty() =3D=3D true, "Mu= lti-byte empty() is wrong");
    static_assert(wide.empty= ()<= span style=3D"color: #000;" class=3D"styled-by-prettify"> =3D=3D true, "Wide empty() is wrong");
    static_assert(utf16.empty(= ) <= span style=3D"color: #660;" class=3D"styled-by-prettify">=3D=3D true, "UTF-16 empty() is wrong");
    static_assert(utf32.empty() =3D=3D<= /span> true, "UTF-32 empty() is wrong");

    static_assert(mb =3D=3D ""_cs, "opera= tor=3D=3D() is wrong");
    static_assert(mb != =3D " "_cs, "operator!=3D() is wrong");
}

void testSearching()
{
&n= bsp;   constexpr auto hi =3D "Hello "_cs + "World!"_cs;
    static_assert(hi.find('?') =3D=3D std::string::npos, "find() is wrong");
    static_assert= (hi.find(' ') =3D=3D 5, "find() is wrong");
    static_assert(hi.find(= 'o') =3D=3D 4, "find() is wrong");
    static_assert(hi.find<= /span>("orl"_cs) =3D=3D 7, "find() is wron= g");
   = ; static_a= ssert(hi.rfind('o') =3D=3D 7, "rfind() is wrong");
    static_assert(hi.rfind("el"_cs)= =3D=3D 1, "rfind() is wrong");
}

v= oid testSu= bstringFunctions(){=
   = constexpr= auto big =3D "Hello, World!"_cs;
    constexpr auto smaller =3D big.<= /span>substr<7>();
    constexpr auto lessbig =3D big.cdr();

    static_assert(smaller.size<= /span>() =3D=3D 6, "substr<>() is wrong");
    static_assert(smaller[0UL]= =3D=3D 'W', "substr<>() is wrong");
    static_assert(big.substr<0>= ().at(0) =3D=3D 'H', "substr<>= ;() is wrong");
&= nbsp;   static_assert(big= .substr<12>().at(0) =3D=3D '!', "substr<>() is wrong");
    static_assert(big.size() =3D=3D l= essbig.size() + 1, "cdr()= is wrong"= );
}

void testComparisons()
{
    constexpr auto first =3D = "One"_cs;
    constexpr auto second =3D "Two"_cs;
    constexpr auto last =3D "One"_cs;


    static_assert(first.compare(last) =3D=3D 0, "compare() is wrong");
    static_assert(first.compare(second<= /span>) =3D=3D -1, "c= ompare() is wrong");=
    static_assert(second.<= /span>compare(last) =3D=3D 1, <= /span>"compare() = is wrong")= ;

&= nbsp;   static_assert("A"= _cs =3D=3D "A"_cs, "operator=3D=3D is wrong");
    static_assert("A"_cs !=3D "a= "_cs, "operator!=3D is wrong");
    static_assert= ("a"_cs > "A"_cs, <= /span>"operator&g= t; is wrong");
&n= bsp;   static_assert("1"<= /span>_cs = < "2"_cs, "operator< is wrong");
}

v= oid testCo= nversions(= )
{
    static_assert("0"_cs.to_number() =3D=3D 0, "to_number() is wrong");
    static_assert= ("1"_cs.to_number() =3D=3D 1, "to_number() is wrong");
    static_assert= ("11"_cs.to_number() =3D=3D 11, "to_number() is wrong"<= /span>);
    <= /span>static_asse= rt(= "65535"_cs.to_number() =3D=3D 65535, "to_number() is= wrong");<= /span>
  =   //"= 99kj343"_cs.to_number();

    constexpr ptrdiff_t number =3D "12345"_cs;    static_assert(= number =3D= =3D 12345, "operator size_type is wrong"<= span style=3D"color: #660;" class=3D"styled-by-prettify">);
    <= span style=3D"color: #800;" class=3D"styled-by-prettify">//constexpr ptrdif= f_t positive =3D "+1"_cs;
    //static_assert(positive =3D=3D 1, "to_number() is = wrong");}=

void testConcatenation= ()
{
    constexpr auto hello =3D "Hello"_cs;<= /span>
  =   con= stexpr auto world =3D "World"_cs;

    constexpr auto together =3D hello + ", "_cs + world + "!"_cs;    static_assert(t= ogether.size<= span style=3D"color: #660;" class=3D"styled-by-prettify">() =3D=3D 13, "operator+ is wrong");
    static_assert(together[5UL] =3D=3D ',', "operator+ is wrong");
}

templ= ate <typename Str>
struct star_wars_speaker
{
    star_wars_speaker() { std::cout << "Someo= ne in Star Wars" <= ;< std<= /span>::endl; }
};

template <= ;>
<= /span>struct star_wars_spea= ker<decltype("I'd just as soon kiss a= Wookiee"_= cs)>
{
    star_wars_= speaker()<= /span> { std::cout << "Carrie Fisher" << std::e= ndl; }
};

template <>
struct star_wars_speaker<decltype("Luke,= I am your father"_cs)>
= {
    s= tar_wars_speaker() <= /span>{ std::cout << "James Earl Jones" << std::endl; }
};

template <>
struct star_wars_speaker<decltype("Midi-chlorians"_cs)>
{
  &nb= sp; star_wars_speaker() { std::cout << "Liam Neeson" << std::endl; }
};

void testClassTemplates()
{
    auto one =3D star_wars_speaker<decltype("I= 'd just as soon kiss a Wookiee"_cs)>();
    auto two =3D star_wars_speaker<decltype("Luke, = I am your father"_cs= )>();    auto= thr =3D star_wars_s= peaker<= decltype("Midi-chlorian"_cs)>();
    = auto fur =3D star_wars_speaker<decltype("How wude!"_cs)>();
}


template = <typena= me = Str>
void star_trek_speak(const Str &){=
   = std::cout << "Someone in Star Trek" << std::endl;
}

template= <><= /span>
= void star_trek_speak= (const decltype("Illogical captain"_cs) &)
{<= /span>
  =   std= ::cout << "Leonard Nimoy" << std::endl;
}

template = <>
<= span style=3D"color: #008;" class=3D"styled-by-prettify">void star_trek_speak<= span style=3D"color: #660;" class=3D"styled-by-prettify">(const decltype("He's dead Jim"_cs) &)
{
  &n= bsp; std::= cout <<= "DeForest Kelley" << std::endl;
}

template = <>
<= span style=3D"color: #008;" class=3D"styled-by-prettify">void star_trek_speak<= span style=3D"color: #660;" class=3D"styled-by-prettify">(const decltype("Oh my"_cs) &= ;)
{
    std::cout << "George Takei" << std::endl;
}

void testFunctionTemplat= es()
{
    star_trek_spe= ak(= "Illogical captai= n"_cs);
    star_= trek_speak= ("He's dea= d Jim"_cs<= /span>);
    s= tar_trek_speak("Oh m= y"_cs);
    star_= trek_speak= ("Khaaaaaa= aaaaannnnnn!"_cs);
<= span style=3D"color: #660;" class=3D"styled-by-prettify">}

int main()
{
    testSizes();
    testEmptyStrings();
    testSubstringFu= nctions();=
 =   testComparisons();
    testConversions();
    testConcatenation();
    testClassTempla= tes();
  &nb= sp; testFunctionTemplates();

    return 0;<= /span>
= }



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