initonly
initonly indicates that variable assignment can only occur as part of the declaration or in a static constructor in the same class.
initonly is a context-sensitive keyword; see Context-Sensitive Keywords for more information.
Example
// mcpp_initonly.cpp
// compile with: /clr /c
ref struct Y1 {
initonly
static int staticConst1;
initonly
static int staticConst2 = 0;
static Y1() {
staticConst1 = 0;
}
};