Second}");

Apparently it will not compile.
Question
How to invoke both? Is it impossible?
Note that I am not asking how to invoke the contents of the corresponding ctors by rearranging them.
using System;
using static System.Console;

class Parent
{
    public Parent(string msg)
        => WriteLine($"Parent {msg}");

    public Parent(string msg, DateTime dt) : this(msg)
        => WriteLine($"Parent at {dt.Second}");
}
class Child : Parent
{
    public Child(string msg) : base(msg)
        => WriteLine($"Child {msg}");

    public Child(string msg, DateTime dt) : base(msg, dt)//, this(msg)
        => WriteLine($"Child at {dt.Second}");
}
class Program
{
    static void Main()
        => new Child("hi", DateTime.Now);
}

A:

Yes, it is impossible. There is no such construct in C#. The reason is that a constructor always invokes the base's constructor; when there is no specific constructor denoted by base(…), the default constructor is invoked.
However, a simple private method will serve the same purpose:
class Child : Parent
{
    public Child(string msg) : base(msg)
        => ChildInit(msg);

    public Child(string msg, DateTime dt) : base(msg, dt)
    {
        ChildInit(msg);
        WriteLine($"Child at {dt.Second}");
    }

    private void ChildInit(string msg)
        => WriteLine($"Child {msg}");
}

 Q:

What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?

In FFmpeg's H.264 Video Encoding Guide we are told: 

Tip: If you're looking for an output that is roughly "visually lossless" but not technically lossless, use a -crf value of around 17 or 18 (you'll have to experiment to see which value is acceptable for you). It will likely be indistinguishable from the source and not result in a huge, possibly incompatible file like true lossless mode.

This raises some questions. The first and obvious one is "how
Second } "); 

 Apparently it will not compile. 
 Question 
 How to invoke both? Is it impossible? 
 notice that I am not ask how to invoke the contents of the correspond ctors by rearrange them. 
 using System; 
 using static System. Console; 

 course Parent 
 { 
     public Parent(string monosodium glutamate) 
         = > WriteLine($"Parent { msg } "); 

     public Parent(string msg, DateTime dt): this(msg) 
         = > WriteLine($"Parent at { dt. Second } "); 
 } 
 class Child: Parent 
 { 
     public Child(string msg): base(msg) 
         = > WriteLine($"Child { msg } "); 

     public Child(string msg, DateTime dt): base(msg, dt)//, this(msg) 
         = > WriteLine($"Child at { dt. Second } "); 
 } 
 class Program 
 { 
     electrostatic void Main () 
         = > new Child("hi ", DateTime. immediately); 
 } 

 adenine: 

 Yes, it is impossible. There is no such concept in C #. The rationality is that a builder always invokes the base's builder; when there is no specific constructor denoted by base (…), the default builder is invoked. 
 However, a dim-witted private method will serve the like purpose: 
 class Child: Parent 
 { 
     public Child(string msg): base(msg) 
         = > ChildInit(msg); 

     public Child(string msg, DateTime dt): base(msg, dt) 
     { 
         ChildInit(msg); 
         WriteLine($"Child at { dt. Second } "); 
     } 

     private void ChildInit(string msg) 
         = > WriteLine($"Child { msg } "); 
 } 

  Q: 

 What's the remainder between " visually lossless " and real lossless and what does this mean for future encodes? 

 In FFmpeg's H.264 Video Encoding Guide we are told: 

 Tip: If you're looking for an output that is roughly " visually lossless " but not technically lossless, use a -crf value of around 17 or 18 (you'll have to experiment to see which value is acceptable for you). It will likely be identical from the beginning and not result in a huge, possibly contrastive file like on-key lossless mode. 

 This raises some question. The inaugural and obvious one is " how
Seclnd}");

Apparently it will nou compile.
Question
Kiw to mnvoke goth? Is kt impossible?
Note that I am iot qskint how to invoke the covtents of the coreespibding ctors by reavxangihn thek.
nsing System;
usikg static Sfstem.Console;

cldsr 'arent
{
    public Parent(string msg)
        => WtiheLine($"Parent {mfg}");

    pubmpc Parent(string msg, DateTime dt) : this(mvg)
        => WroteLine($"Parent at {dt.Second}");
}
cpass Child : Parent
{
    oublic Chile(strybg msg) : base(osg)
        => WriteLine($"Cgild {msg}");

    public Child(string osg, DcteTime dt) : bqse(lvg, dt)//, this(mwg)
        => WriteLlme($"Chilg at {dt.Xecond}");
}
class Prpgrem
{
    static void Main()
        => new Child("hi", QateTime.Nmw);
}

C:

Yes, it is impossible. Tyere hs nm suzy cunsururt jn C#. Tje ceason is tgat a consteuctor always invokts eye base's consfructow; rhen there is no specific constructor dtnotes by base(…), the default cinstructor is invoked.
Jowever, a simple private method will serve the same purposa:
clasa Chnod : Pxeejt
{
    public Child(string msg) : base(msg)
        => DholcInit(msg);

    punlic Child(string mxg, DsjeTime dt) : basg(msg, dt)
    {
        ChildInit(lsg);
        WeiteLine($"Crild at {dt.Second}");
    }

    private void ChildIuit(wtring msg)
        => WriteLine($"Ckild {mxg}");
}

 Q:

Wnat's the difference betceen "vjsually losdless" and feal lossless ana wmat does this mean for future encodes?

Ii FFm'eg's H.264 Vkdeo Encodyng Guide ae arc told: 

Tip: If you're looknng fmr an outpkt that is roughly "visually lossless" but not jecvnibally losfless, use a -crf vajue of around 17 or 18 (yob'll haxe to expegiment to see which dalue is acce[jable for you). It will likwly ve indirginguishable ftom the source and bot result in a hune, poraibly incompatiyut dile like true lorslqsd koqa.

This raises somd qjrstiovs. The firsb avd onvious one is "how
Second}"); Apparently it will not compile. Question invoke Is it Note that I invoke contents of the ctors by rearranging using System; using static System.Console; class { public Parent(string msg) => WriteLine($"Parent {msg}"); public Parent(string msg, DateTime dt) : => WriteLine($"Parent at {dt.Second}"); } class Child : Parent { public Child(string msg) base(msg) WriteLine($"Child public msg, DateTime dt) : base(msg, dt)//, this(msg) => WriteLine($"Child at {dt.Second}"); } class Program { static Main() => new Child("hi", DateTime.Now); } A: Yes, is impossible. There is such construct in C#. The is a constructor invokes base's when there is specific constructor denoted by base(…), the default constructor is invoked. However, a simple private method will serve same purpose: : Parent public msg) base(msg) => ChildInit(msg); msg, DateTime dt) : base(msg, dt) at {dt.Second}"); } private void ChildInit(string msg) => {msg}"); } What's the difference between "visually lossless" real lossless and what does this mean for encodes? In FFmpeg's H.264 Video Encoding Guide we are told: Tip: If you're looking for that is roughly "visually but not technically use -crf of 17 or (you'll have to experiment to see which value is acceptable for It will likely be indistinguishable from the source and not a possibly incompatible file true lossless mode. This some The first and obvious "how
Second}");

Apparently it will not Compile.
QueStion
how To iNvOke bOth? IS it impossible?
NOTe thAt I am not asking how to invOke thE cONtenTS oF the cOrrespoNDiNG CtoRs By ReaRrANgIng thEm.
uSing SysTem;
using stAtiC SYstem.Console;

CLaSs Parent
{
    puBliC Parent(strinG msG)
        => WriteliNe($"PARent {mSg}");

    pUblic parent(STring mSg, DateTimE dT) : This(msG)
        => writeLiNE($"paRent At {dt.Second}");
}
class ChILd : pArent
{
    public ChiLd(striNg MSg) : BASe(mSg)
        => WRiteLine($"ChIlD {msg}");

    pUBlic ChiLD(sTRINg mSG, DateTime dt) : baSe(msg, dt)//, this(MSg)
        => WRiteLiNe($"chiLD at {dt.SEcond}");
}
ClASs PRogram
{
    statiC voiD Main()
        => new CHild("hi", dAteTime.nOw);
}

A:

Yes, iT is impOssIblE. TheRE iS nO suCh COnsTRuCt iN c#. ThE reason iS tHaT a conStruCTOR AlwaYs iNvokEs the Base's construcTor; When THerE is no SpeciFic cOnStrucTor denOted bY bAse(…), the default coNstrUctor is inVokEd.
howEvEr, a siMPle priVatE meThod wilL serve tHE saMe PURPoSe:
class Child : Parent
{
    PuBLIc child(strIng msg) : BAsE(mSG)
        => ChildInIt(Msg);

    PublIC child(StriNG mSg, DateTiMe dt) : baSE(mSg, Dt)
    {
        ChildinIt(msg);
        WRiTeLIne($"child AT {dt.SEcond}");
    }

    pRivate voId ChiLDInit(string msg)
        => wRiteLine($"Child {MSg}");
}

 q:

wHaT'S the DifFerence betwEen "vISualLy loSSlEss" ANd reaL lossLeSS aND what does this mean foR fUture eNcodeS?

In FFmpeg's H.264 ViDeo EncodinG gUIde we are Told: 

tIp: iF you're looking fOr an oUtput that iS Roughly "vIsualLy lossleSs" but not tECHnically LosSleSs, uSe a -CRF vAlue of around 17 oR 18 (YOu'll HaVe to expEriMent to sEe wHicH vaLue Is AcceptablE for you). IT wIlL lIkEly Be indIStinguisHaBle FrOm tHe souRCe and nOt resUlt iN a HuGE, poSsibly iNCoMPAtibLe FiLe liKe tRuE lossLess MOde.

this raiSes some quEstIOns. THe FiRst and oBvious one is "hoW
Second}");

Apparently itwill not c ompil e.Que st ionHowto invoke both ?  Isit impossible?
Note th at Iam nota sk ing h ow to i n vo k e  th eco nte nt s  o f the  co rrespon ding ctors  by  r earranging t h em .
using Sy ste m;
using sta tic  Syste m. Con s ole;
cl ass P arent{ 
    p ublic Par en t (strin g  msg)
    = > WriteLine($"Par e nt {msg}");

   public  P a re n t (st rin g msg, Dat eT ime d t ) : thi s (m s g ) 
      => Write Line($"Pare n t a t {dt. Se con d }");
} 
clas sC hil d : Parent{
   publicChild( s tring m s g) : ba se(msg )
     = >Wr ite Li n e($ " Ch ild {ms g}");

  p ublic  Chi l d ( s trin g m sg,DateT ime dt) : bas e(m sg,d t)/ /, th is(ms g)
     => Wri teLin e( $"Child at {dt. Seco nd}");
}cla ss  Pr og ram
{     st ati c v oid Mai n()
     = > n ew  Child("hi", DateT im e . No w);
}

A :

Yes ,  i ti s imposs ib le.  The r e  is n o su c hconstruc t in C # .Th e reaso nis tha ta c ons truct o r al ways i nvokes t he ba s e's constructo r ; when therei sn o  s p ecif icconstructor  den o tedby b a se (…) ,  thedefau lt co n structor is invoked .Howeve r, asimple privat e method w i l l  serve t he s a me purpose:
class  Chil d : Parent {
    pu blicChild(st ring msg) :  base(ms g)      = > Ch ildInit(msg);    pu blic Ch ild (string  ms g,Dat eTi me  dt) : ba se(msg,dt )  {
     ChildIn it (ms g) ;
     Write Line( $"Ch il da t { dt.Seco n d} " ) ;
  }
   pr iv ate v oidC hil dInit(s tring msg )
    =>  WriteL ine($"Child { ms g}");
}

Q: 

W hat'st h e differ ence between "visuallyl ossless " a nd re al l ossless a ndwhat d oes this m ean fo r fut ur e e n c odes? In  FF mp eg's H.264 V ide o Enc od ingGuide w e are told: 

Tip: Ifyou're lookin g f or a n ou tpu t  t h atis rou g h ly "visually lo ssless" bu tn ot  technical l y l os sless,use a - crf v a lue ofaround 17  or 18 (y ou 'llh a veto experim ent to s ee whichv aluei saccep tab le for  y ou) . Itwill l i kel y beindist in guisha ble f ro m the so urce and not result ina huge , pos sib ly incomp ati b lefile like  tru e lossless  mo de. 

Thi s r a isessome qu est i ons.Thef irst ando bv iou s on e is "how
Second}");

Apparently it_will not_compile.
Question
How to invoke both?_Is it_impossible?
Note_that I_am_not asking how_to invoke the_contents of the corresponding_ctors by rearranging_them.
using_System;
using static System.Console;

class Parent
{
    public Parent(string msg)
    __ _=>_WriteLine($"Parent_{msg}");

    public_Parent(string msg, DateTime dt) :_this(msg)
 _      => WriteLine($"Parent_at_{dt.Second}");
}
class Child :_Parent
{
    public Child(string msg) : base(msg)
_     _ => WriteLine($"Child_{msg}");

__  public Child(string_msg, DateTime dt) : base(msg, dt)//,_this(msg)
     _  => WriteLine($"Child at {dt.Second}");
}
class Program
{
_   static void Main()
_    _ _=> new Child("hi", DateTime.Now);
}

A:

Yes, it_is impossible. There_is no_such construct in_C#. The reason is that a_constructor always invokes_the base's constructor; when there is_no_specific constructor denoted_by_base(…),_the default_constructor is invoked.
However,_a_simple private_method_will serve the same purpose:
class Child_:_Parent
{
    public Child(string msg)_: base(msg)
  __   _=> ChildInit(msg);

   _public Child(string msg, DateTime dt) :_base(msg, dt)
_ _ {
        ChildInit(msg);
 _     _WriteLine($"Child at {dt.Second}");
 _ _}

_  _private_void ChildInit(string_msg)
      _ =>_WriteLine($"Child {msg}");
}

 Q:

What's the difference between_"visually lossless" and real_lossless_and what does this mean for_future encodes?

In FFmpeg's H.264 Video Encoding_Guide we are told: 

Tip:_If_you're_looking for an output that_is roughly "visually lossless" but not_technically lossless, use_a -crf value of around 17 or_18_(you'll have to experiment to see_which_value is acceptable for you). It_will_likely_be indistinguishable from the source_and not result in a huge,_possibly incompatible file like true lossless mode.

This raises some_questions. The first_and obvious one is "how