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Parameters: draft a family of pre-conditioning operations

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- we need a generic operation to clamp to the smaller value domain
 - furthermore we need a virtual function to apply a type specific limiter

__TODO__: this draft does not handle properly signed vs. unsigned types
This commit is contained in:
Fischlurch 2026-07-20 23:12:24 +02:00
parent 7d35790e11
commit 11bb3bce73
3 changed files with 227 additions and 10 deletions
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77
src/lib/par/domain.hpp
View file

@ -38,11 +38,20 @@
//#include "lib/meta/typelist-util.hpp"
#include "lib/meta/generator.hpp"
#include "lib/meta/trait.hpp"
#include "lib/util.hpp"
#include <concepts>
#include <limits>
namespace lib {
namespace par {
using std::same_as;
using std::floating_point;
using std::numeric_limits;
struct ValBuff { /*placeholder*/ };
template<typename X>
@ -116,6 +125,8 @@ namespace par {
public:
virtual ~Domain(); ///< this is an interface
virtual void applyLimit (ValBuff&) =0;
protected:
};
@ -131,7 +142,7 @@ _Pragma("GCC diagnostic ignored \"-Woverloaded-virtual\"")
template<typename U>
struct TypeSetup
struct DomainSetup
{
template<typename X, class BAS>
@ -148,33 +159,83 @@ _Pragma("GCC diagnostic ignored \"-Woverloaded-virtual\"")
template<typename X>
class BaseDomain
: public TypeSetup<X>::TypeHandlerChain
: public DomainSetup<X>::TypeHandlerChain
{
public:
void applyLimit (ValBuff&) override;
};
/* ===== type conversion details ===== */
template<typename SUB, typename BAS>
concept sub_domain = std::signed_integral<SUB> != std::signed_integral<BAS>
or std::numeric_limits<SUB>::max() < std::numeric_limits<BAS>::max()
or std::numeric_limits<SUB>::lowest() > std::numeric_limits<BAS>::lowest()
;
/** generic helper to conform into a common value domain
* @tparam SUB the implied target value domain
* @tparam BAS source data type
* @return a value in source data type,
* yet conformed into the target data range
*/
template<typename SUB, typename BAS>
inline constexpr BAS
preClamp (BAS const& value)
{
return value;
}
/** special case: clamp the source value into the target value domain */
template<typename SUB, typename BAS> requires sub_domain<SUB,BAS>
inline constexpr BAS
preClamp (BAS const& rawVal)
{
auto upperBound = numeric_limits<SUB>::max();
auto lowerBound = numeric_limits<SUB>::lowest();
return util::limited (lowerBound, rawVal, upperBound);
}
/** special case: trigger a bool at the 0.5 level */
template<same_as<bool> B, floating_point F>
inline constexpr F
preClamp (F const& rawVal)
{
return 0.5 < rawVal? F{1} : F{0};
}
template<typename X>
inline void
BaseDomain<X>::applyLimit (ValBuff& valBuff)
{
X& val{asValue<X> (valBuff)};
val = preClamp<X> (val);
}
template<typename U>
template<typename X, class BAS>
inline void
TypeSetup<U>::TypeHandlerImpl<X,BAS>::extractAs (X& targetVal, ValBuff const& valBuff)
DomainSetup<U>::TypeHandlerImpl<X,BAS>::extractAs (X& targetVal, ValBuff const& valBuff)
{
if constexpr (std::is_assignable_v<X&, U const&>)
if constexpr (std::is_assignable_v<X&, U&&>)
{
targetVal = asValue<U> (valBuff);
targetVal = preClamp<X> (asValue<U> (valBuff));
}
else
if constexpr (std::is_constructible_v<X, U const&>)
if constexpr (std::is_constructible_v<X, U&&>)
{
targetVal.~X();
new(&targetVal) X (asValue<U> (valBuff));
new(&targetVal) X (preClamp<X> (asValue<U> (valBuff)));
}
else
static_assert (!sizeof(X), "this type conversion is not supported");
}
}} // namespace lib::par
#endif /*LIB_PAR_DOMAIN_H*/

25
tests/lib/par/parameter-domain-test.cpp
View file

@ -70,6 +70,7 @@ namespace test{
{
seedRand();
basics();
verify_valueLimits();
verify_valueAccess();
}
@ -80,6 +81,30 @@ namespace test{
}
void
verify_valueLimits()
{
SHOW_EXPR(preClamp<int> (23))
SHOW_EXPR(preClamp<int> (-55))
SHOW_EXPR(preClamp<uint> (23))
SHOW_EXPR(preClamp<uint> (-55))
SHOW_EXPR((sub_domain<uint,int>))
SHOW_EXPR((sub_domain<int,uint>))
SHOW_EXPR((sub_domain<short,long>))
SHOW_EXPR(std::numeric_limits<uint>::max())
SHOW_EXPR(std::numeric_limits<int>::max())
SHOW_EXPR(std::numeric_limits<uint>::lowest())
SHOW_EXPR(std::numeric_limits<int>::lowest())
// concept sub_domain = std::numeric_limits<SUB>::max() < std::numeric_limits<BAS>::max()
// or std::numeric_limits<SUB>::lowest() > std::numeric_limits<BAS>::lowest()
//SHOW_EXPR(std::numeric_limits<uint>::lowest() > std::numeric_limits<int>::lowest())
//SHOW_EXPR(abs(std::numeric_limits<uint>::lowest()) < (std::numeric_limits<int>::lowest()))
SHOW_EXPR(preClamp<short> (INT64_MAX))
SHOW_EXPR(preClamp<short> (INT64_MIN))
}
void
verify_valueAccess()
{

135
wiki/thinkPad.ichthyo.mm
View file

@ -82211,7 +82211,9 @@
</node>
</node>
</node>
<node CREATED="1782948792629" ID="ID_1623866120" MODIFIED="1782949000542" TEXT="a Parameter has...">
<node BACKGROUND_COLOR="#ffcea1" CREATED="1782948792629" ID="ID_1623866120" MODIFIED="1784583297397" TEXT="a Parameter has...">
<cloud COLOR="#e8ceb0"/>
<icon BUILTIN="forward"/>
<node CREATED="1782948801636" ID="ID_224051194" MODIFIED="1783012188400" TEXT=" a Disposition"/>
<node CREATED="1783012199995" ID="ID_1245050792" MODIFIED="1783012219836" TEXT="which comprises">
<node CREATED="1783012221304" ID="ID_1384741652" MODIFIED="1783012226307" TEXT="the ParamType">
@ -82971,7 +82973,7 @@
</html></richcontent>
</node>
</node>
<node COLOR="#352c84" CREATED="1784491298401" ID="ID_427305032" MODIFIED="1784491357026" TEXT="Fazit {generiertes Mulit-TypeHandler-OO-Interface}">
<node COLOR="#352c84" CREATED="1784491298401" ID="ID_427305032" MODIFIED="1784491298401" TEXT="Fazit {generiertes Multi-TypeHandler-OO-Interface}">
<font BOLD="true" NAME="SansSerif" SIZE="12"/>
<icon BUILTIN="forward"/>
<node CREATED="1784491360016" ID="ID_711986937" MODIFIED="1784491537887" TEXT="das Original-Baumuster von Alexandrescu ist immer noch die beste L&#xf6;sung">
@ -83040,6 +83042,131 @@
<icon BUILTIN="yes"/>
</node>
</node>
<node BACKGROUND_COLOR="#d8b58c" COLOR="#930225" CREATED="1784502897450" ID="ID_1330060370" LINK="https://stackoverflow.com/a/19921030/444796" MODIFIED="1784503377607" TEXT="Nebenbei bemerkt: std::is_assignable verh&#xe4;lt sich &#xbb;unintuitiv&#xab;">
<font NAME="SansSerif" SIZE="12"/>
<icon BUILTIN="idea"/>
<node BACKGROUND_COLOR="#e0ceaa" COLOR="#bb050f" CREATED="1784503389623" ID="ID_1439488420" MODIFIED="1784503437563" TEXT="is_assignable_v&lt;int,int&gt; &#x2261; false">
<icon BUILTIN="broken-line"/>
</node>
<node CREATED="1784503100809" ID="ID_1277115906" MODIFIED="1784503126112" TEXT="weil es definiert ist per std::declval&lt;X&gt;()"/>
<node CREATED="1784503127869" ID="ID_1665184398" MODIFIED="1784503141705" TEXT="und ein unqualifizierter Typ hier eine RValue-Refernz liefert"/>
<node CREATED="1784503156556" ID="ID_1901180022" MODIFIED="1784503174041" TEXT="man kann das so deuten: ein Literal ist nicht zuweisbar">
<icon BUILTIN="idea"/>
</node>
<node CREATED="1784503185446" ID="ID_472398753" MODIFIED="1784503227927" TEXT="mu&#xdf; also immer bedenken, da&#xdf; man normalerweise eine Referenz auf ein Objekt bekommt">
<richcontent TYPE="NOTE"><html>
<head/>
<body>
<p>
das ist implizites Standard-Verhalten von C++ in praktisch jedem Ausdruck und Funktionsaufruf
</p>
</body>
</html></richcontent>
</node>
</node>
<node COLOR="#435e98" CREATED="1784590564427" ID="ID_1119403748" MODIFIED="1784590780419" TEXT="sollte auch noch limitieren">
<arrowlink COLOR="#4490cf" DESTINATION="ID_1748150865" ENDARROW="Default" ENDINCLINATION="-102;-5;" ID="Arrow_ID_1245799800" STARTARROW="None" STARTINCLINATION="-15;97;"/>
<icon BUILTIN="yes"/>
</node>
</node>
<node CREATED="1784583466853" ID="ID_1381198266" MODIFIED="1784583478931" TEXT="erweitere auf &#xbb;conforiming&#xab;-Funktionalit&#xe4;t">
<node CREATED="1784583493969" ID="ID_1551792524" MODIFIED="1784583530626">
<richcontent TYPE="NODE"><html>
<head/>
<body>
<p>
das ist die <i>zweite H&#228;lfte</i>&#160;des Domain-Begriffs
</p>
</body>
</html></richcontent>
<node CREATED="1784583588306" ID="ID_479207205" MODIFIED="1784583601739">
<richcontent TYPE="NODE"><html>
<head/>
<body>
<p>
Basis ist ein Typ als <i>Grundgesammtheit</i>
</p>
</body>
</html></richcontent>
</node>
<node CREATED="1784583605161" ID="ID_1455528542" MODIFIED="1784583626539" TEXT="zusammen mit einer Wert-Einschr&#xe4;nkung"/>
<node BACKGROUND_COLOR="#e0ceaa" COLOR="#690f14" CREATED="1784583633429" ID="ID_246137093" MODIFIED="1784583668394" TEXT="Vorsicht: an Vektor-f&#xf6;rmige Typen denken...">
<richcontent TYPE="NOTE"><html>
<head/>
<body>
<p>
z.B. Farben
</p>
</body>
</html></richcontent>
<icon BUILTIN="messagebox_warning"/>
<node CREATED="1784583901650" ID="ID_66120766" MODIFIED="1784583966561" TEXT="hier zeigt sich ein komplexes Verh&#xe4;ltnis zwischen Domain und BaseDomain">
<richcontent TYPE="NOTE"><html>
<head/>
<body>
<p>
naiver Weise dachte ich erst, eine Domain ist lediglich ein Teilintervall einer BaseDomain. Tja zu fr&#252;h gefreut
</p>
</body>
</html></richcontent>
</node>
</node>
</node>
<node CREATED="1784583716571" ID="ID_38727535" MODIFIED="1784583732840" TEXT="das Conforming mu&#xdf; u.U mehrstufig sein">
<icon BUILTIN="messagebox_warning"/>
<node CREATED="1784583737728" ID="ID_388891052" MODIFIED="1784583753674" TEXT="ein erster Schritt mu&#xdf; in der Quell-Domain erfolgen">
<node BACKGROUND_COLOR="#fafe99" COLOR="#fa002a" CREATED="1784593401491" ID="ID_1670494263" MODIFIED="1784593411005" TEXT="Vorsicht Falle: signed vs unsigned">
<icon BUILTIN="broken-line"/>
<node CREATED="1784593415546" ID="ID_985867046" MODIFIED="1784593437214" TEXT="die numeric-Limits werden im jeweiligen Typ angegeben"/>
<node CREATED="1784593442299" ID="ID_814649582" MODIFIED="1784593459136" TEXT="bei direkten Vergleichen passiert zwar die erwartete Promotion"/>
<node COLOR="#5b280f" CREATED="1784593459863" ID="ID_492548018" MODIFIED="1784593634425" TEXT="aber signed vs. unsigned- Werte lassen sich &#xfc;berhaupt nicht ohne Weiteres vergleichen">
<arrowlink COLOR="#c30d0f" DESTINATION="ID_1240698281" ENDARROW="Default" ENDINCLINATION="318;0;" ID="Arrow_ID_1820583210" STARTARROW="None" STARTINCLINATION="195;6;"/>
<icon BUILTIN="closed"/>
</node>
</node>
</node>
<node CREATED="1784583754452" ID="ID_1524391258" MODIFIED="1784583768830" TEXT="dann kann innerhalb der Wert-BaseDomain eine weitere Einschr&#xe4;nkung folgen"/>
<node CREATED="1784586543839" ID="ID_1702195769" MODIFIED="1784586550867" TEXT="Teil-Operationen">
<node CREATED="1784586551999" ID="ID_1288354893" MODIFIED="1784586565918" TEXT="preClamp&lt;TAR&gt; (SRC const&amp;)">
<node CREATED="1784586572069" ID="ID_70379943" MODIFIED="1784586582520" TEXT="l&#xe4;&#xdf;t sich komplett generisch implementieren"/>
<node CREATED="1784586675600" ID="ID_876196754" MODIFIED="1784588546088" TEXT="concept sub_domain&lt;SUB,BAS&gt;">
<node BACKGROUND_COLOR="#e0ceaa" COLOR="#a4060f" CREATED="1784593517692" ID="ID_1240698281" MODIFIED="1784593627634" TEXT="mu&#xdf; hier signed &#x2260; unsigned explizit pr&#xfc;fen">
<richcontent TYPE="NOTE"><html>
<head/>
<body>
<p>
sonst geht der nachfolgende Vergleich f&#252;r die untere Schwelle ganz glorreich in die Hose, sch&#246;nen Gru&#223; vom uint(-1)
</p>
</body>
</html></richcontent>
<linktarget COLOR="#c30d0f" DESTINATION="ID_1240698281" ENDARROW="Default" ENDINCLINATION="318;0;" ID="Arrow_ID_1820583210" SOURCE="ID_492548018" STARTARROW="None" STARTINCLINATION="195;6;"/>
</node>
</node>
<node COLOR="#338800" CREATED="1784593545688" ID="ID_1890105632" MODIFIED="1784593569629" TEXT="kann au&#xdf;erdem gleich das Trigger-Verhalten f&#xfc;r Booleans implementieren">
<icon BUILTIN="button_ok"/>
</node>
</node>
<node CREATED="1784587186873" ID="ID_1998060966" MODIFIED="1784587208674" TEXT="virtual applyLimit(Buffer&amp;)">
<node CREATED="1784587905137" ID="ID_196992570" MODIFIED="1784587939787" TEXT="f&#xfc;r BaseDomain&lt;X&gt; &#x27f5; folgt direkt aus numeric_limits&lt;X&gt;"/>
<node CREATED="1784588869240" ID="ID_1210483864" MODIFIED="1784588882120" TEXT="kann man auf die generische constexpr preClamp zur&#xfc;ckf&#xfc;hren">
<icon BUILTIN="idea"/>
</node>
</node>
</node>
</node>
</node>
<node CREATED="1784588917160" ID="ID_174389664" MODIFIED="1784588970730" TEXT="beide Zuweisungs-Operationen auf Basis des &#xbb;conforming&#xab;- reimplementieren">
<node CREATED="1784589831498" HGAP="30" ID="ID_1748150865" MODIFIED="1784591447465" TEXT="denn auch beim Extrahieren kann eine Limitierung notwendig sein" VSHIFT="-6">
<richcontent TYPE="NOTE"><html>
<head/>
<body>
<p>
wir wollen explizit kein uint(-1) haben
</p>
</body>
</html></richcontent>
<linktarget COLOR="#4490cf" DESTINATION="ID_1748150865" ENDARROW="Default" ENDINCLINATION="-102;-5;" ID="Arrow_ID_1245799800" SOURCE="ID_1119403748" STARTARROW="None" STARTINCLINATION="-15;97;"/>
</node>
</node>
</node>
</node>
@ -184807,6 +184934,10 @@ class Something
<icon BUILTIN="messagebox_warning"/>
</node>
</node>
<node BACKGROUND_COLOR="#e0ceaa" COLOR="#8c0041" CREATED="1784503310882" ID="ID_376662071" MODIFIED="1784503330829" TEXT="woot">
<icon BUILTIN="smiley-oh"/>
<node CREATED="1784503253634" ID="ID_1878512579" LINK="#ID_1330060370" MODIFIED="1784503258591" TEXT="std::is_assignable verh&#xe4;lt sich &#xbb;unintuitiv&#xab;"/>
</node>
</node>
</node>
<node CREATED="1450488895106" ID="ID_1586185818" MODIFIED="1557498707240" TEXT="Threading">