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Groups > comp.lang.c++ > #87736

Re: initial size of a std::vector of std::strings

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c++
Subject Re: initial size of a std::vector of std::strings
Date 2022-12-07 13:49 -0800
Organization None to speak of
Message-ID <87edta6g0a.fsf@nosuchdomain.example.com> (permalink)
References <tmp947$g0jv$1@dont-email.me> <tmptcb$hm5s$1@dont-email.me> <tmquhd$kuud$1@dont-email.me>

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Lynn McGuire <lynnmcguire5@gmail.com> writes:
[...]
> I am trying to declare a vector with max_ncp strings in a struct.
> struct component_data {
> 	std::vector <std::string> component_names [max_ncp];
> 	doublereal heatoffusionatmeltingpoint [max_ncp];
> 	doublereal meltingpointtemperature [max_ncp];
> 	doublereal sublimationtemperature [max_ncp];
> 	doublereal triplepointtemperature [max_ncp];
> 	doublereal triplepointpressure [max_ncp];
> };
>
> Visual Studio 2015 does not like
>    	std::vector <std::string> component_names (max_ncp);
> or
> 	std::vector <std::string> component_names (max_ncp, "");

How does it express its dislike?  Both work for me:

#include <vector>
#include <string>
#include <iostream>

int main() {
    int max_ncp = 42;
    {
        std::vector<std::string> component_names(max_ncp);
        std::cout << component_names.size() << ' ';
    }
    {
        std::vector<std::string> component_names(max_ncp, "");
        std::cout << component_names.size() << '\n';
    }
}

The output is "42 42".

> But it does like
> 	std::vector <std::string> component_names [max_ncp];
> But it does not work.

That defines an array (not a std::array, just a C-style array object) of
max_ncp vectors.  I think you want a single vector.

Do you want to set the initial size or the initial capacity?

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

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Thread

initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-06 23:42 -0600
  Re: initial size of a std::vector of std::strings James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-12-07 00:52 -0500
  Re: initial size of a std::vector of std::strings Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-07 08:17 +0100
  Re: initial size of a std::vector of std::strings Öö Tiib <ootiib@hot.ee> - 2022-12-07 00:23 -0800
    Re: initial size of a std::vector of std::strings Juha Nieminen <nospam@thanks.invalid> - 2022-12-07 09:13 +0000
      Re: initial size of a std::vector of std::strings Öö Tiib <ootiib@hot.ee> - 2022-12-07 06:03 -0800
        Re: initial size of a std::vector of std::strings Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-07 15:37 +0100
          Re: initial size of a std::vector of std::strings Öö Tiib <ootiib@hot.ee> - 2022-12-07 09:33 -0800
            Re: initial size of a std::vector of std::strings Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-07 18:45 +0100
      Re: initial size of a std::vector of std::strings Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-07 16:34 +0200
        Re: initial size of a std::vector of std::strings Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-07 15:38 +0100
        Re: initial size of a std::vector of std::strings Juha Nieminen <nospam@thanks.invalid> - 2022-12-08 07:58 +0000
    Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 16:28 -0600
      Re: initial size of a std::vector of std::strings Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-07 14:53 -0800
        Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 16:56 -0600
        Re: initial size of a std::vector of std::strings Juha Nieminen <nospam@thanks.invalid> - 2022-12-08 08:03 +0000
  Re: initial size of a std::vector of std::strings "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-12-07 12:28 +0100
    Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 14:54 -0600
      Re: initial size of a std::vector of std::strings "daniel...@gmail.com" <danielaparker@gmail.com> - 2022-12-07 13:16 -0800
      Re: initial size of a std::vector of std::strings "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-12-07 22:33 +0100
        Re: initial size of a std::vector of std::strings Bonita Montero <Bonita.Montero@gmail.com> - 2022-12-07 22:37 +0100
      Re: initial size of a std::vector of std::strings Michael S <already5chosen@yahoo.com> - 2022-12-07 13:34 -0800
        Re: initial size of a std::vector of std::strings Bo Persson <bo@bo-persson.se> - 2022-12-07 23:48 +0100
      Re: initial size of a std::vector of std::strings Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-07 13:49 -0800
        Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 16:01 -0600
          Re: initial size of a std::vector of std::strings Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-07 14:47 -0800
            Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 17:09 -0600
      Re: initial size of a std::vector of std::strings Bo Persson <bo@bo-persson.se> - 2022-12-07 23:45 +0100
        Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-07 17:08 -0600
  Re: initial size of a std::vector of std::strings Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-08 01:44 -0600

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