uCalc API Version: 2.1.3-preview.2 Released: 6/16/2026

Warning

uCalc API Preview Release Notice:The documentation describes the intended behavior of the API. The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.

ValuePtr(POINTER)

Method

Product: 

Fast Math Parser

Class: 

Item

Sets the memory address stored within a pointer-type variable, changing what the variable points to.

Syntax

ValuePtr(POINTER)

Parameters

pointerAddress
POINTER
The memory address to be stored in the pointer variable.

Return

void

This method does not return a value.

Remarks

The ValuePtr(POINTER) method sets the memory address stored within a pointer-type variable, effectively changing which memory location the variable points to. It is the primary way to programmatically assign a target to a pointer that has been defined using DefineVariable.

ValuePtr() vs. ValueAddr()

Understanding the difference between these concepts is crucial for pointer manipulation:

  • item.ValueAddr(): Gets the address of the item itself.
  • item.ValuePtr(address): Sets the value stored inside the item to be a new address.

This method is the programmatic equivalent of the = assignment operator for pointers in an expression. The following are functionally identical:

// Programmatic assignmentptrVar.ValuePtr(targetVar.ValueAddr());// Expression-based assignmentuc.Eval("ptrVar = AddressOf(targetVar)");

Why uCalc? (Comparative Analysis)

In native languages, pointer assignment is a fundamental but low-level operation.

  • vs. C++: The uCalc line ptr.ValuePtr(target.ValueAddr()) is the safe, managed equivalent of the C++ statement ptr = ⌖. uCalc's system ensures that pointer types are handled correctly across the C++/C#/VB language barrier.
  • vs. C# unsafe code: To manipulate pointers directly in C#, you typically need to use an unsafe block, which introduces complexity and potential instability. uCalc provides a safe abstraction layer, allowing you to perform pointer assignments without leaving the managed code environment.

This makes ValuePtr a key feature for creating high-performance links between uCalc variables and data buffers in the host application.

Examples

DefineVariable; using pointers
				
					using uCalcSoftware;

var uc = new uCalc();
var Int8Var = uc.DefineVariable("x As Int8 = -1");
var Int16Var = uc.DefineVariable("y As Int16 = -1");
var StrVar = uc.DefineVariable("MyStr = 'Hello there'");
Console.WriteLine(uc.EvalStr("x"));
Console.WriteLine(uc.EvalStr("y"));
Console.WriteLine(uc.EvalStr("MyStr"));

var xPtr = uc.DefineVariable("xPtr As Pointer"); // General pointer
var yPtr = uc.DefineVariable("yPtr As Int16u Ptr"); // pointer specific to unsigned Int16
var yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)"); // Using AddressOf
var StrPtr = uc.DefineVariable("StrPtr As String Ptr");
xPtr.ValuePtr(Int8Var.ValueAddr()); // Sets the pointer address
yPtr.ValuePtr(Int16Var.ValueAddr()); // Note: address of signed Int16 going to an unsigned Ptr
StrPtr.ValuePtr(StrVar.ValueAddr());

// Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
Console.WriteLine(uc.EvalStr("ValueAt(Int8u, xPtr)")); // Type required because it's defined as generar pointer
Console.WriteLine(uc.EvalStr("ValueAt(yPtr)")); // Type name not needed because it's defined as Int16u Ptr
Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"));
Console.WriteLine(uc.EvalStr("ValueAt(StrPtr)"));

// Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
// to see data type names you can use with ValueAt

var OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234");
uc.DataTypeOf(BuiltInType.Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr());

Console.WriteLine(uc.EvalStr("OtherInt"));
Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"));





				
			
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto Int8Var = uc.DefineVariable("x As Int8 = -1");
   auto Int16Var = uc.DefineVariable("y As Int16 = -1");
   auto StrVar = uc.DefineVariable("MyStr = 'Hello there'");
   cout << uc.EvalStr("x") << endl;
   cout << uc.EvalStr("y") << endl;
   cout << uc.EvalStr("MyStr") << endl;

   auto xPtr = uc.DefineVariable("xPtr As Pointer"); // General pointer
   auto yPtr = uc.DefineVariable("yPtr As Int16u Ptr"); // pointer specific to unsigned Int16
   auto yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)"); // Using AddressOf
   auto StrPtr = uc.DefineVariable("StrPtr As String Ptr");
   xPtr.ValuePtr(Int8Var.ValueAddr()); // Sets the pointer address
   yPtr.ValuePtr(Int16Var.ValueAddr()); // Note: address of signed Int16 going to an unsigned Ptr
   StrPtr.ValuePtr(StrVar.ValueAddr());

   // Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
   cout << uc.EvalStr("ValueAt(Int8u, xPtr)") << endl; // Type required because it's defined as generar pointer
   cout << uc.EvalStr("ValueAt(yPtr)") << endl; // Type name not needed because it's defined as Int16u Ptr
   cout << uc.EvalStr("ValueAt(yPtrB)") << endl;
   cout << uc.EvalStr("ValueAt(StrPtr)") << endl;

   // Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
   // to see data type names you can use with ValueAt

   auto OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234");
   uc.DataTypeOf(BuiltInType::Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr());

   cout << uc.EvalStr("OtherInt") << endl;
   cout << uc.EvalStr("ValueAt(yPtrB)") << endl;





}
				
			
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim Int8Var = uc.DefineVariable("x As Int8 = -1")
      Dim Int16Var = uc.DefineVariable("y As Int16 = -1")
      Dim StrVar = uc.DefineVariable("MyStr = 'Hello there'")
      Console.WriteLine(uc.EvalStr("x"))
      Console.WriteLine(uc.EvalStr("y"))
      Console.WriteLine(uc.EvalStr("MyStr"))
      
      Dim xPtr = uc.DefineVariable("xPtr As Pointer") '// General pointer
      Dim yPtr = uc.DefineVariable("yPtr As Int16u Ptr") '// pointer specific to unsigned Int16
      Dim yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)") '// Using AddressOf
      Dim StrPtr = uc.DefineVariable("StrPtr As String Ptr")
      xPtr.ValuePtr(Int8Var.ValueAddr()) '// Sets the pointer address
      yPtr.ValuePtr(Int16Var.ValueAddr()) '// Note: address of signed Int16 going to an unsigned Ptr
      StrPtr.ValuePtr(StrVar.ValueAddr())
      
      '// Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
      Console.WriteLine(uc.EvalStr("ValueAt(Int8u, xPtr)")) '// Type required because it's defined as generar pointer
      Console.WriteLine(uc.EvalStr("ValueAt(yPtr)")) '// Type name not needed because it's defined as Int16u Ptr
      Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"))
      Console.WriteLine(uc.EvalStr("ValueAt(StrPtr)"))
      
      '// Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
      '// to see data type names you can use with ValueAt
      
      Dim OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234")
      uc.DataTypeOf(BuiltInType.Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr())
      
      Console.WriteLine(uc.EvalStr("OtherInt"))
      Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"))
      
      
      
      
      
   End Sub
End Module
				
			
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