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[niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ?

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I've been a long time far from C++ and I realize I have 
forgotten most, and moreover don't understand "modern" C++ 
.... anyway

When in a function (member or not is irrelevant) I build an 
aggregate object (class / struct, possibly nested with 
other), and this aggregate has a DEFAULT public constructor 
which does not resort to new or new [], but then the said 
former function invokes some class methods that DO some 
dynamic allocation, and then the function returns passing 
outside a copy by-value of the built object to the caller, 
placed "partially" on the stack, the final copy will be 
shallow or deep ?
With shallow I mean : every automatic member not requiring 
new or new [], with deep copy I mean exact copy (or even the 
temporary itself ...).

another maybe relevant detail
is it relevant whether the COPY constructor is defined or 
the default one ? How behaves a default generated copy 
constructor ? Does it perform also new/ new [] operations ?

Is it really the COPY constructor that is called on such a 
situation (returning a complex type by-value instead of 
by-pointer) ?

or a COPY constructor is given, which does not do deep copy, 
but just "automatic" data is replicated.


In case I defined a COPY constructor making dynamic 
allocation, is it : 1) required, 2) optional or 3) 
deprecated and possibly dangerous define also an explicit 
DESTRUCTOR making cleanups ?

TY

-- 
1) Resistere, resistere, resistere.
2) Se tutti pagano le tasse, le tasse le pagano tutti
Soviet_Mario - (aka Gatto_Vizzato)

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[niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 00:00 +0200
  Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Öö Tiib <ootiib@hot.ee> - 2019-07-15 15:40 -0700
    Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 01:18 +0200
      Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-07-15 21:12 -0400
        Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 14:28 +0200
          Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-07-16 09:47 -0400
            Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 17:16 +0200
              Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-07-16 10:30 -0700
                Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 19:44 +0200
          Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Rosario19 <Ros@invalid.invalid> - 2019-07-23 09:28 +0200
      Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Öö Tiib <ootiib@hot.ee> - 2019-07-15 20:22 -0700
        Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 14:37 +0200
          Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Öö Tiib <ootiib@hot.ee> - 2019-07-17 01:41 -0700
  Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Paavo Helde <myfirstname@osa.pri.ee> - 2019-07-16 15:04 +0300
    Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Soviet_Mario <SovietMario@CCCP.MIR> - 2019-07-16 14:42 +0200
      Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Paavo Helde <myfirstname@osa.pri.ee> - 2019-07-16 16:15 +0300
      Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-07-16 10:07 -0400
  Re: [niubbo] aggregate types built in a function and returned by value (on stack). Shallow or Deep copy ? Juha Nieminen <nospam@thanks.invalid> - 2019-07-17 07:36 +0000

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