CODEWITHSUNDEEP
c++
luk_chesnok_xren
luk_chesnok_xren

Reputation: 147

What is meaning no declaration match error in my case?

I described class in different files:

3DObjectDescription.h

#pragma once
#include <SFML/Graphics.hpp>
#include <NumCpp.hpp>
#include "MoveMatrix.h"

class Object3D
{
public:
    nc::NdArray<float> vertexes;

    nc::NdArray<float> faces;

    Object3D();

    void translation(float tX, float tY, float tZ);
    void rotate_x(float angle);
    void rotate_y(float angle);
    void rotate_z(float angle);
    void scale_(float scale_c);

};

3DObjectDescription.cpp

#include "3DObjectDescription.h"

Object3D::Object3D()
{
    vertexes = {{0,0,0,1}, {0,1,0,1}, {1,1,0,1}, {1,0,0,1},
                {0,0,1,1}, {0,1,1,1}, {1,1,1,1}, {1,0,1,1}};

    faces = {{0,1,2,3}, {4,5,6,7}, {0,4,5,1}, {2,3,7,6}, {1,2,6,5}, {0,3,7,4}};
}

Object3D::translation(float tX, float tY, float tZ)
{
    vertexes = nc::dot(vertexes, translate(tX, tY, tZ));
}

Object3D::rotate_x(float angle_)
{
    vertexes = nc::dot(vertexes, rotation_X(angle_));
}

Object3D::rotation_y(float angle_)
{
    vertexes = nc::dot(vertexes, rotation_Y(angle_));
}

Object3D::rotation_z(float angle)
{
    vertexes = nc::dot(vertexes, rotation_Z(angle_));
}

Object3D::scale_(float scale_c)
{
    vertexes = nc::dot(vertexes, scale(scale_c));
}

When I compiling it, I get errors:

error: no declaration matches 'int Object3D::translation(float, float, float)'
error: no declaration matches 'int Object3D::rotate_x(float)'
error: no declaration matches 'int Object3D::rotation_y(float)'
error: no declaration matches 'int Object3D::rotation_z(float)'
error: no declaration matches 'int Object3D::scale_(float)'

I dont know from where did the integer type come from, when I didnt declared it! And I had never met such error!

Upvotes: 1

Views: 23781

Answers (2)

ap-osd
ap-osd

Reputation: 2834

The declaration return type is void.
void translation(float tX, float tY, float tZ);
 ^^^^

But your definition does not have a type.
void Object3D::translation(float tX, float tY, float tZ)
 ^^^^ is missing

When an explicit return type is missing, `int` is assumed by some compilers producing that error.

e.g. VS2019 error:
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

Upvotes: 3

Brian61354270
Brian61354270

Reputation: 14423

All of the definitions in 3DObjectDescription.cpp are missing return types in their signatures.

Simply update their signatures to include the void return type. The definition for Object3D::translation should read

void Object3D::translation(float tX, float tY, float tZ)
{
    vertexes = nc::dot(vertexes, translate(tX, tY, tZ));
}

Likewise for the rest.

The reason that your compiler is complaining about mismatched signatures instead of indicating a syntax error is because your compiler is implicitly assuming a return type of int when none is specified. This is a holdover from C. However, this idiosyncrasy was removed in C++, so your compiler is exhibiting non-standard behavior by attempting to compile it.

Upvotes: 2

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