已经缩小转换误差在Android NDK C ++手臂 [英] Have narrowing conversion error in C++ arm from Android NDK

问题描述

我已经从Android的NDK C ++手臂收缩转换错误。

拥有以下code：

  int16_t AX = li.A.x，AY = li.A.y;
int16_t BX = li.B.x，通过= li.B.y;
Rect16 RCA = {斧 -  8，AY  -  8时，AX + 8，+ AY 8};
Rect16 RCB = {BX  -  8日，由 -  8，BX + 8，+由8};
 

和得到这个错误，当尝试编译：

 错误：的缩小转换（（（int）的AY）+ -0x00000000000000008）'从'诠释'到'int16_t里面{}
 

Rect16结构：

  typedef结构tagRect16 {
    int16_t左，上，右，下;
} Rect16;
 

8 编译器说 -

解决方案

您的问题的事实，在EX pression 唉茎您正在呼叫 INT操作符（INT，INT）。你需要告诉编译器8是一个短，使用方法像的这个问题。

I have narrowing conversion error in C++ arm from Android NDK.

Have a following code:

int16_t ax = li.A.x, ay = li.A.y;
int16_t bx = li.B.x, by = li.B.y;
Rect16 rcA = { ax - 8, ay - 8, ax + 8, ay + 8 };
Rect16 rcB = { bx - 8, by - 8, bx + 8, by + 8 };

And get this error, when try to compile:

error: narrowing conversion of '(((int)ay) + -0x00000000000000008)' from 'int' to 'int16_t' inside { }

Rect16 struct:

typedef struct tagRect16 {
    int16_t left, top, right, bottom;
} Rect16;

解决方案

Your problem stems from the fact that in the expression ay - 8 the compiler says you are calling int operator-(int, int). You need to tell the compiler that 8 is a short, using a method like in this question.

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